fbpx
Wikipedia

SARS-CoV-2 Omicron variant

Omicron (B.1.1.529) is a variant of SARS-CoV-2 first reported to the World Health Organization (WHO) by the Network for Genomics Surveillance in South Africa on 24 November 2021.[10][11] It was first detected in Botswana and has spread to become the predominant variant in circulation around the world.[12] Following the original B.1.1.529 variant, several subvariants of Omicron have emerged including: BA.1, BA.2, BA.3, BA.4, and BA.5.[13] Since October 2022, two subvariants of BA.5 called BQ.1 and BQ.1.1 have emerged.

SARS-CoV-2 Variant
Omicron
Scientifically accurate atomic model of the external structure of SARS-CoV-2. Each "ball" is an atom.
General details
WHO DesignationOmicron
LineageB.1.1.529
First detectedSouth Africa
Date reported24 November 2021; 2 years ago (2021-11-24)
StatusVariant of concern
Symptoms
Asymptomatic infection,[1] body ache,[1] cough,[1] fainting,[2] fatigue,[3] fever, headache,[4] loss of smell or taste,[5][6] — less common nasal congestion or running nose[4] night sweats,[7] — unique Omicron symptom, upper respiratory tract infection[8] skin rash,[9] sneezing,[4] sore throat[2]
Major variants

Three doses of a COVID-19 vaccine provide protection against severe disease and hospitalisation caused by Omicron and its subvariants.[14][15][16][17] For three-dose vaccinated individuals, the BA.4 and BA.5 variants are more infectious than previous subvariants but there is no evidence of greater sickness or severity.[13][18][19]

Classification edit

 
Omicron variant and other major or previous variants of concern of SARS-CoV-2 depicted in a tree scaled radially by genetic distance, derived from Nextstrain on 1 December 2021

On 26 November 2021, the WHO's Technical Advisory Group on SARS-CoV-2 Virus Evolution declared PANGO lineage B.1.1.529 a variant of concern and designated it with the Greek letter omicron.[10] The WHO skipped the preceding letters nu and xi in the Greek alphabet to avoid confusion with the similarities of the English word "new" and the Chinese surname Xi.[20]

The name of the variant has occasionally been mistaken as "Omnicron" among some English speakers, due to a lack of familiarity with the Greek alphabet, and the relative frequency of the Latin prefix "omni" in other common speech.[21][22]

The GISAID project has assigned it the clade identifier GR/484A,[23] and the Nextstrain project has assigned it the clade identifiers 21K and 21L, both belonging to a larger Omicron group 21M.[24]

History edit

Omicron was first detected on 22 November 2021 in laboratories in Botswana and South Africa based on samples collected on 11–16 November,[25] with the first known samples collected in Johannesburg, South Africa on 8 November 2021.[26] The first known cases outside of South Africa were two people who travelled on 11 November: one who flew from South Africa to Hong Kong via Qatar, and another who travelled from Egypt to Belgium via Turkey.[27][28] On 26 November 2021, WHO designated B.1.1.529 as a variant of concern and named it "Omicron", after the fifteenth letter in the Greek alphabet.[10] As of 6 January 2022, the variant had been confirmed in 149 countries.[29]

Origin hypotheses edit

Omicron did not evolve from any other variant, but instead diverged on a distinct track, perhaps in mid-2020.[29][30] Competing hypotheses are being examined.

One origin hypothesis is that various mutations in the Omicron variant, comprising a 9-nucleotide sequence, may have been acquired from another coronavirus (known as HCoV-229E), responsible for the common cold.[31] This is not entirely unexpected — at times, viruses within the body acquire and swap segments of genetic material from each other, and this is one common means of mutation.[31]

A link with HIV infection may explain a large number of mutations in the sequence of the Omicron variant.[32] Indeed, in order to be affected by such a high number of mutations, the virus must have been able to evolve a long time without killing its host, which can occur in people with a weakened immune system who receive enough medical care to survive.[32][33] This is the case in HIV patients in South Africa, who represent about 14% of the population (as of 2017).[34] HIV prevention could be key to reducing the risk of uncontrolled HIV driving the emergence of SARS-CoV-2 variants.[32]

One hypothesis to explain the novel mutations is that SARS-CoV-2 was transmitted from humans to mice and mutated in a population of mice sometime between mid-2020 and late 2021 before reinfecting humans.[30]

On 1 December 2022, a team of researchers from the Charité (Berlin) published a now-retracted study in Science (journal) that claimed that "data revealed genetically diverse Omicron ancestors already existed across Africa by August 2021".[35] After a re-analysis because of doubts,[36] the team retracted the article on 20 December 2022 due to contamination of the samples.[37][38]

Spread edit

On 24 November 2021, the variant was first reported to the WHO from South Africa based on samples that had been collected from 14 to 16 November.[25] South African scientists were first alerted by samples from the very beginning of November where the PCR tests had S gene target failure (occurs in a few variants, but not in Delta which dominated in the country in October) and by a sudden increase of COVID-19 cases in Gauteng; sequencing revealed that more than 70 percent of samples collected in the province between 14 and 23 November were a new variant.[39]

The first confirmed specimens of Omicron were collected on 8 November 2021 in South Africa and on 9 November in Botswana.[40] Likely Omicron (SGTF) samples had occurred on 4 November 2021 in Pretoria, South Africa.[citation needed]

When WHO was alerted on 24 November, Hong Kong was the only place outside Africa that had confirmed a case of Omicron; one person who traveled from South Africa on 11 November, and another traveler who was cross-infected by this case while staying in the same quarantine hotel.[27]

On 25 November, one confirmed case was identified in Israel from a traveler returning from Malawi,[41] along with two who returned from South Africa and one from Madagascar.[42] All four initial cases reported from Botswana occurred among fully vaccinated individuals.[43]

On 26 November, Belgium confirmed its first case; an unvaccinated person who had travelled from Egypt via Turkey on 11 November.[28] All three initial confirmed and suspected cases reported from Israel occurred among fully vaccinated individuals,[41] as did a single suspected case in Germany.[44]

On 27 November, two cases were detected in the United Kingdom, another two in Munich, Germany and one in Milan, Italy.[45]

On 28 November, 13 cases were confirmed in the Netherlands among the 624 airline passengers who arrived from South Africa on 26 November.[46] Confirmation of a further 5 cases among these passengers followed later.[47] Entry into the Netherlands generally required having been vaccinated or PCR-tested, or having recovered. The passengers of these two flights had been tested upon arrival because of the newly imposed restrictions (which were set in place during their flight), after which 61 tested positive for SARS-CoV-2.[48] A further two cases were detected in Australia. Both people landed in Sydney the previous day, and travelled from southern Africa to Sydney Airport via Doha Airport. The two people, who were fully vaccinated, entered isolation; 12 other travellers from southern Africa also entered quarantine for fourteen days, while about 260 other passengers and crew on the flight were directed to isolate.[49] Two travellers from South Africa who landed in Denmark tested positive for COVID-19; it was confirmed on 28 November that both carried the Omicron variant.[50][51] On the same day, Austria also confirmed its first Omicron case.[52] A detected Omicron case was reported in the Czech Republic, from a traveler who spent time in Namibia.[53] Canada also reported its first Omicron cases, with two from travelers from Nigeria, therefore becoming the first North American country to report an Omicron case.[54]

On 29 November, a positive case was recorded in Darwin, Australia. The person arrived in Darwin on a repatriation flight from Johannesburg, South Africa on 25 November, and was taken to a quarantine facility, where the positive test was recorded.[55] Two more people who travelled to Sydney from southern Africa via Singapore tested positive.[56] Portugal reported 13 Omicron cases, all of them members of a soccer club.[57] Sweden also confirmed their first case on 29 November,[58] as did Spain, when a traveler came from South Africa.[59]

On 30 November, the Netherlands reported that Omicron cases had been detected in two samples dating back as early as 19 November.[60] A positive case was recorded in Sydney from a traveller who had visited southern Africa before travel restrictions were imposed, and was subsequently active in the community.[61] Japan also confirmed its first case.[62] Two Israeli doctors tested positive and entered isolation. Both of them had received three shots of the Pfizer vaccine prior to testing positive.[63] In Brazil, three cases of the Omicron variant were confirmed in São Paulo.[64] Another five are under suspicion.[65][66] A person in Leipzig, Germany with no travel history nor contact with travellers tested positive for Omicron.[67]

On 1 December, the Omicron variant was detected in three samples in Nigeria that had been collected from travelers from South Africa within the last week.[68][69] On the same day, public health authorities in the United States announced the country's first confirmed Omicron case. A resident of San Francisco who had been vaccinated returned from South Africa on 22 November, began showing mild symptoms on 25 November[70] and was confirmed to have a mild case of COVID-19 on 29 November.[71] Ireland and South Korea also reported their first cases.[72] South Korea reported its cases from five travelers arriving in South Korea from Nigeria.[73]

On 2 December, Dutch health authorities confirmed that all 14 passengers with confirmed Omicron infection on 26 November had been previously vaccinated.[74] The same day, the Norwegian Institute of Public Health confirmed that 50 attendees of a company Christmas party held at a restaurant in Norway's capital, Oslo, were infected with the Omicron variant.[75] France has confirmed only 25 cases of the new Omicron variant but officials say the number could jump significantly in the coming weeks.[76]

By 6 December, Malaysia confirmed its first case of the variant. The case was a South African student entering to study at a private university.[77] In Namibia, 18 cases out of 19 positive COVID-19 samples that had been collected between 11 and 26 November were found to be Omicron, indicating a high level of prevalence in the country.[78] Fiji also confirmed two positive cases of the variant. They travelled from Nigeria arriving in Fiji on November 25.[79]

On 9 December, Richard Mihigo, coordinator of the World Health Organisation's Immunisation and Vaccine Development Programme for Africa, announced that Africa accounted for 46% of reported cases of the Omicron variant globally.[80]

On 13 December, the first death of a person with Omicron was reported in the UK.[81]

On 16 December, New Zealand confirmed its first case of the Omicron variant, an individual who had traveled from Germany via Dubai.[82]

The first death of a person with Omicron was reported in Germany on 23 December[83] and in Australia on 27 December.[84]

By Christmas 2021, the Omicron Strain became dominant in the US.[85]

On 3 January 2022, South Korea reported the first two deaths of people who tested positive post mortem for Omicron.[86]

In February 2022, Omicron accounted for 98% of publicly available genetic sequences worldwide.[87]

On 29 March 2022, Omicron subvariant BA.2 overtook BA.1 and became the dominant strain in the U.S.[88][89][90]

As of May 2022, BA.2.12.1 was spreading in the US and two new subvariants of Omicron named BA.4 and BA.5, first detected in January 2022, spread in South Africa. All 3 subvariants have spike protein mutations of L452 and elude immunity from prior BA1 infection.[91]

On 16 March 2023, without seeing a reduction in the threat to public health, the WHO stopped classifying Omicron as a variant of concern in order to maintain this classification only for new threats. Instead, the WHO classified its subvariants as variants of interest and under monitoring.[87]

Reactions edit

Vaccine producers edit

On 26 November 2021, BioNTech said it would know in two weeks whether the current vaccine is effective against the variant and that an updated vaccine could be shipped in 100 days if necessary. AstraZeneca, Moderna and Johnson & Johnson were also studying the variant's impact on the effectiveness of their vaccines.[92] On the same day, Novavax stated that it was developing an updated vaccine requiring two doses for the Omicron variant, which the company expected to be ready for testing and manufacturing within a few weeks.[93][94] On 29 November 2021, The Gamaleya Institute said that Sputnik Light should be effective against the variant, that it would begin adapting Sputnik V, and that a modified version could be ready for mass production in 45 days.[95] Sinovac said it could quickly mass-produce an inactivated vaccine against the variant and that it was monitoring studies and collecting samples of the variant to determine if a new vaccine is needed.[96]

On 7 December 2021, at a symposium in Brazil with its partner Instituto Butantan, Sinovac said it would update its vaccine to the new variant and make it available in three months.[97] On 2 December, the Finlay Institute was already developing a version of Soberana Plus against the variant.[98] Pfizer hoped to have a vaccine targeted to immunize against Omicron ready by March 2022.[99]

World Health Organization edit

On 26 November 2021, the WHO asked nations to enhance surveillance and sequencing efforts, submit complete genome sequences and associated metadata to a publicly available database, such as GISAID, report initial cases/clusters associated with virus-of-concern infection to WHO through the IHR mechanism, where capacity exists and in coordination with the international community, perform field investigations and laboratory assessments to improve understanding of the potential impacts of the virus of concern on COVID-19 epidemiology, severity, and the effectiveness of public health and social measures, diagnostic methods, immune responses, antibody neutralization, or other relevant characteristics.[100] On 26 November 2021, WHO advised countries not to impose new restrictions on travel, instead recommending a "risk-based and scientific" approach to travel measures.[101] On the same day, the European Centre for Disease Prevention and Control (ECDC) reported modeling indicating that strict travel restrictions would delay the variant's impact on European countries by two weeks, possibly allowing countries to prepare for it.[102] As with other variants, the WHO recommended that people continue to keep enclosed spaces well ventilated, avoid crowding and close contact, wear well-fitting masks, clean hands frequently, and get vaccinated.[103][104] On 29 November 2021, the WHO said cases and infections were expected among those vaccinated, albeit in a small and predictable proportion.[105]

International response edit

After the WHO announcement, on the same day, several countries announced travel bans from southern Africa in response to the identification of the variant, including the United States, which banned travel from eight African countries,[106] although as of 30 November 2021 it notably did not ban travel from any European countries, Israel, Canada, or Australia where cases were also detected at the time the bans were announced. Other countries that also implemented travel bans include Japan, Canada, the European Union, Israel, Australia, the United Kingdom, Singapore, Malaysia, Indonesia, Morocco, and New Zealand.[107][108]

On 26 November 2021 the Brazilian Health Regulatory Agency recommended flight restrictions regarding the new variant.[109] The state of New York declared a state of emergency ahead of a potential Omicron spike, although no cases had yet been detected in the state or the rest of the United States.[110] On 27 November 2021, Switzerland introduced obligatory tests and quarantine for all visitors arriving from countries where the variant was detected, which originally included Belgium and Israel.[111]

On 26 November 2021 South African Minister of Health Joe Phaahla defended his country's handling of the pandemic and said that travel bans went against the "norms and standards" of the World Health Organization.[112]

Some speculated that travel bans could have a significant impact on South Africa's economy by limiting tourism and could lead to other countries with economies that are reliant on tourism to hide the discovery of new variants of concern. Low vaccine coverage in less-developed nations could create opportunities for the emergence of new variants, and these nations also were struggling to gain intellectual property to develop and produce vaccines locally.[113] At the same time, inoculation had slowed in South Africa due to vaccine hesitancy and apathy, with a nationwide vaccination rate of only 35% as of November 24, 2021.[114]

On 29 November 2021, the WHO warned countries that the variant poses a very high global risk with severe consequences and that they should prepare by accelerating vaccination of high-priority groups and strengthening health systems. WHO director-general Tedros Adhanom described the global situation as dangerous and precarious and called for a new agreement on the handling of pandemics, as the current system disincentivizes countries from alerting others to threats that will inevitably land on their shores. CEPI CEO Richard Hatchett said that the variant fulfilled predictions that transmission of the virus in low-vaccination areas would accelerate its evolution.[105]

In preparation for the Omicron variant arriving in the United States, President Joe Biden stated that the variant is "cause for concern, not panic", reiterated that the government was prepared for the variant and would have it under control and that large-scale lockdowns, similar to the ones in 2020 near the beginning of the pandemic, were "off the table for now."[115]

In mid-December 2021, multiple Canadian provinces reinstated restrictions on gatherings and events such as sports tournaments, and tightened enforcement of proof of vaccination orders. British Columbia expressly prohibited any non-seated "organized New Year's Eve event",[116][117][118] while Quebec announced a partial lockdown on 20 December 2021, ordering the closure of all bars, casinos, gyms, schools, and theatres, as well as imposing restrictions on the capacity and operating hours of restaurants, and the prohibition of spectators at professional sporting events.[119]

On 18 December 2021, the Netherlands government announced a lockdown intended to prevent spread of the variant during the holiday period.[120]

In late December 2021, some countries shortened the typical six-month interval for a booster dose of the vaccine to prepare for a wave of Omicron, as two doses are not enough to stop the infection. UK, South Korea and Thailand reduced to three months; Belgium, four months; France, Singapore, Taiwan, Italy and Australia, five months. Finland reduced it to three months for risk groups. Other countries continued with a six-month booster schedule. While antibody levels begin to drop at four months, a longer interval usually allows time for the immune system's response to mature.[121]

Market reactions edit

On 26 November 2021, worry about the potential economic impact of the Omicron variant led to a drop in global markets, including the worst drop of the Dow Jones Industrial Average in 2021, led by travel-related stocks. The price of Brent Crude and West Texas Intermediate oil fell 10% and 11.7%, respectively[122] Cryptocurrency markets were also routed.[123][124] and the South African rand also hit an all-time low for 2021, trading at over 16 rand to the dollar, losing 6% of its value in November.[125][126][127]

In early December 2021, Jerome Powell, the chairman of the Federal Reserve, testified before the U.S. Senate Committee on Banking that "The recent rise in COVID-19 cases and the emergence of the Omicron variant pose downside risks to employment and economic activity and increased uncertainty for inflation."[128]

Biology edit

 
The genomic sequence of the Omicron variant is pictured above

Mutations edit

As of June 2022, Omicron had about 50 mutations relative to the Wuhan-Hu-1 or B variant,[129][130] which is more than any previous SARS-CoV-2 variant. Thirty-two of these pertained to the spike protein, which most vaccines target to neutralise the virus.[131] As of December 2021, many mutations were novel and not found in previous variants.[40] As of April 2022 the variant was characterised by 30 amino acid changes, three small deletions, and one small insertion in the spike protein compared with the original virus, of which 15 are located in the receptor-binding domain (residues 319–541).[132] As of December 2022 the virus carried a number of changes and deletions in other genomic regions. For example, three mutations at the furin cleavage site, which facilitates its transmission.[133][134]

 
 
Illustration of the locations of the Omicron mutations in the spike protein, top view (left) and side view (right), showing amino acid substitutions (yellow), deletions (red), and insertions (green). In this trimeric structure, two monomers (gray and light blue) have their receptor-binding domains in the "down" conformation while one (dark blue) is in the "up" or "open" conformation. Mutation data from WHO,[103] structure from PDB: 6VYB​.[135]
 
Comparison of mutation prevalence for ORF1a, ORF1b, and S genes of Omicron lineages that are designated Variants of Concern. Characteristic mutations for a lineage are defined as nonsynonymous substitutions or deletions that occur in > 75% of sequences within that lineage.[136]

Subvariants edit

Several subvariants of Omicron have been discovered and new ones continue to emerge.[12] There are 310 Pango lineages[clarification needed] currently associated with the Omicron variant.[137] The 'standard' sublineage is now referred to as BA.1 (or B.1.1.529.1), and the two other sublineages are known as BA.2 (or B.1.1.529.2) and BA.3 (or B.1.1.529.3).[138] In mid-2022, BA.4 (or B.1.1.529.4) and BA.5 (or B.1.1.529.5) were detected in several countries.[139] They share many mutations, but also significantly differ. In general, BA.1 and BA.2 share 32 mutations, but differ by 28.[140] BA.1 has itself been divided in two, the original BA.1 and BA.1.1 (or B.1.1.529.1.1) where the main difference is that the latter has a R346K mutation.[141]

Standard PCR and rapid tests continue to detect all Omicron subvariants as COVID-19, but further tests are necessary to distinguish the subvariants from each other and from other COVID-19 variants.[142]

Defining mutations in the
SARS-CoV-2 Omicron variant
Gene Amino acid
ORF1ab nsp3: K38R
nsp3: V1069I
nsp3: Δ1265
nsp3: L1266I
nsp3: A1892T
nsp4: T492I
nsp5: P132H
nsp6: Δ105-107
nsp6: A189V
nsp12: P323L
nsp14: I42V
Spike A67V
Δ69-70
T95I
G142D,
Δ143-145
Δ211
L212I
ins214EPE
G339D
S371L
S373P
S375F
K417N
N440K
G446S
S477N
T478K
E484A
Q493R
G496S
Q498R
N501Y
Y505H
T547K
D614G
H655Y
N679K
P681H
N764K
D796Y
N856K
Q954H
N969K
L981F
E T9I
M D3G
Q19E
A63T
N P13L
Δ31-33
R203K
G204R
Sources: UK Health Security Agency[143] CoVariants[24]

BA.2 edit

BA.2 was first detected in a sample from 15 November 2021.[144] A preprint released in February 2022 (published in May) suggested that BA.2 was more transmissible than BA.1 and may cause more severe disease.[145] This was later disproven by a study in late-October 2022, that found BA.2 actually caused less severe disease relative to BA.1 (which in turn, caused less severe disease compared to the delta variant).[146] Therapeutic monoclonal antibodies used to treat people infected with COVID-19 did not have much effect on BA.2, which was "almost completely resistant" to casirivimab and imdevimab, and 35 times more resistant to sotrovimab than the BA.1 subvariant.[citation needed]

Spread edit

As of 17 January 2022, BA.2 had been detected in at least 40 countries and in all continents except Antarctica.[147] By 31 January, it had been detected in at least 57 countries.[148] In global samples collected from 4 February to 5 March and uploaded to GISAID, BA.2 accounted for c. 34%, compared to 41% for BA.1.1, 25% for BA.1 and less than 1% for BA.3.[149] In a review two weeks later, covering 16 February to 17 March, BA.2 had become the most frequent.[150][151] Based on GISAID uploads, BA.1 peaked in early January 2022, after which it was overtaken by both BA.1.1 and BA.2.[152] In North America, parts of Europe and parts of Asia, BA.1 was first outcompeted by BA.1.1. For example, in the United States, France and Japan, BA.1.1 became the dominant subvariant in January 2022.[153][154][155]

By late December 2021/early January 2022, BA.2 had become dominant in parts of India (already making up almost 80 percent in Kolkata in late December 2021[156]) and the Philippines, had become frequent in Scandinavia, South Africa and Singapore, and was showing signs of growth in Germany and the United Kingdom.[157][158][159][160] In Japan, which has quarantine and detailed screening of all international travellers, as of 24 January, the vast majority of BA.2 had been detected in people that had arrived from India or the Philippines with cases going back at least to 1 December 2021 (far fewer BA.1 or other variants were detected among arrivals from the two countries in that period), but small numbers had also been detected in people arriving from other countries.[161][162][163]

In Denmark, the first BA.2 was in a sample collected on 5 December 2021.[164] By week fifty (13–19 December) it had started to increase, with BA.2 being at around 2 percent of sequenced cases compared to 46 percent BA.1 (remaining Delta). The frequency of both Omicron subvariants continued to increase throughout the last half of December; and by the end of the year BA.2 had reached 20 percent and BA.1 peaked at 72 percent. In January 2022, BA.1 began decreasing, whereas BA.2 continued its increase. By the second week of 2022, the frequency of the two was almost equal, both being near 50 percent.[164] In the following week, BA.2 became clearly dominant in Denmark with 65 percent of new cases.[165] Trends from the other Scandinavian countries, India, South Africa and the United Kingdom also showed that BA.2 was increasing in proportion to BA.1.[166][167] In early February 2022, it had become the dominant subvariant in South Africa, in late February it had become dominant in Germany and in early March it had become dominant in the United Kingdom.[168][169][170] In early March, BA.1.1 was still heavily dominant in the United States (having overtaken BA.1 in January), but BA.2 was increasing in frequency, later becoming dominant in the US by 29 March.[153][171]

XE edit

A new BA.1–BA.2 recombinant was isolated in the UK in January 2022, dubbed the "XE" recombinant. It was found by the WHO to be potentially 10% more transmissible than BA.2, making it about 43% to 76% to more transmissible than BA.1, and making the XE recombinant the most contagious variant identified at the time.[172]

BA.2.12 edit

There were two new BA.2 subvariants detected in the US state of New York, which are BA.2.12 (or B.1.1.529.2.12) and BA.2.12.1 (or B.1.1.529.2.12.1), both of which have a significant growth advantage of 23–27% over BA.2 and contributing to a rise in infections in central New York, centred on Syracuse and Lake Ontario, which later became dominant by May 24, 2022, in the US.[173]

BA.2.75 and BA.2.75.2 edit

The subvariant BA.2.75 (or B.1.1.529.2.75, nicknamed Centaurus by the media[174]), first detected in India in May 2022, was classified as variant under monitoring by the WHO.[175] Additional newer mutations in this line (like BA.2.75.2 aka B.1.1.529.2.75.2 or Chiron) may be capable of escaping neutralizing antibodies.[176]

XBB and XBB.1 edit

XBB, a recombinant of the BA.2.10.1.1 and BA.2.75.3.1.1.1 sublineages,[177] is an Omicron subvariant first detected in August 2022.[178]

On 20 October 2022, the chief scientist of the World Health Organization (WHO), Soumya Swaminathan, warned that the XBB subvariant of Omicron may cause infections in some countries while the severity of the new variants is not yet known.[179]

On 9 January 2023 the European CDC said there was suggestive evidence the XBB.1.5 variant had a growth advantage; after becoming dominant in the US, it might become dominant in Europe in the following months.[180] From preliminary evidence, they had assessed the XBB variants had no effect on disease severity and transmissibility.[181]

In early March 2023, XBB.1.16 first appeared in India and caused a surge of hospitalizations.[182] It was nicknamed Arcturus by T. Ryan Gregory.[182][183][184]

EG.5 and EG.5.1 edit

EG.5 (or XBB.1.9.2.5), nicknamed by some media "Eris",[185] is a descendant of XBB.1.9.2. The lineage was detected as early as February 2023.[186] On 6 August, the UK Health Security Agency reported the EG.5 strain was responsible for one in seven new cases in the UK during the third week of July.[187] It was identified as a "variant of interest" by the WHO on 9 August 2023. Its key difference from other strains is a "F456L amino acid mutation".[188]

HV.1 edit

HV.1 (or XBB.1.9.2.5.1.6.1) is a sublineage of XBB.1.9.2, of the Omicron family first detected in July 2023.

HV.1 overtook EG.5 as the dominant subvariant in the U.S. in October 2023.[189] In October experts stated that there was no evidence that HV.1 was more severe or transmissible than other Omicron subvariants.[190]

BA.2.86 edit

In mid-August 2023, the CDC and WHO announced they were monitoring another subvariant of Omicron, BA.2.86, a descendant of the BA.2 subvariant. The WHO has placed BA.2.86 as a VUM (variant under monitoring) as it is reported to have more than 30 mutations.[191] As of 18 August, cases had been reported from four countries: three in Denmark and a single each in Israel, the UK and the US. On the same date, UK healthcare authorities noted that its almost simultaneous appearance in several countries still operating detailed genomic surveillance indicated that it likely already was spreading more widely internationally.[192] The first case of BA.2.86 was collected on 24 July 2023 according to the WHO.

BA.3 edit

The third Omicron sublineage, BA.3, is very rare. It has the same S-gene target failure (SGTF) deletion (Δ69-70) as BA.1.[citation needed]

BA.4 and BA.5 edit

In April 2022, the WHO announced it was tracking the BA.4 and BA.5 subvariants with BA.4 having been detected in South Africa, Botswana, Denmark, Scotland and England.[193] Early indications from data collected in South Africa suggested BA.4 and BA.5 have a significant growth advantage over BA.2, which by 12 May earned the status Variant of Concern by the European Centre for Disease Prevention and Control, and, by 20 May, by the UK Health Security Agency.[194][195][196][197] BA.5 was dominant in Portugal by 25 May, accounting for two-thirds of all new cases there.[198] By 24 June, BA.4 and BA.5 together had become dominant variants in the UK and Germany.[199][200][201][202] These two subvariants became dominant in the United States by 28 June.[203][204] By late June, BA.5 became the dominant subvariant in France, with 59% of new cases linked to it.[205][206]

On 10 May 2022, a case of a new subvariant BA.5.2.1 was reported in California.[207] On 10 July, the city of Shanghai reported its first case of BA.5.2.1, in a man who had flown in from Uganda, sparking a new wave of testing.[208] On 22 July, the province of Ontario, Canada announced that subvariant BA.5.2.1 overtook BA.2.12.1 as the main variant in circulation in Ontario around 2 July.[209] Regeneron is reporting that BA.5.2.1 is the main variant in Australia, Belgium, Brunei, Greece and Iceland.[210] The government of Canada also reported in late June and July, of the travelers arriving by air who test positive for COVID-19, a substantial proportion were BA.5.2.1.[211] BF.7 is a shortened version of the sub-variants full name, which is BA.5.2.1.7. This sub-variant is part of Omicron's BA.5 variant, which had the highest number of reported cases globally, accounting for 76.2% of all cases.[212]

BQ.1 and BQ.1.1 edit

In October 2022, two BA.5 subvariants were found: BQ.1 (or B.1.1.529.5.3.1.1.1.1.1) and BQ.1.1 (or B.1.1.529.5.3.1.1.1.1.1.1).[213][214][215] The variants were originally most prevalent in France.[216] As of 17 November, 93% of sequences in France were Omicron sub-lineage BA.5 and among the BA.5 sub-lineages, BQ.1.1 continued to rise (32% vs 25% in the prior week).[217] In November 2022 in the US it was reported the variants were accounting for 44% of new infections. Early laboratory tests found that these subvariants were better at escaping first and booster vaccines than previous variants.[218]

Transmission edit

 
False-color transmission electron micrograph of an Omicron variant coronavirus, shown in pink, replicating within the cytoplasm of an infected Vero cell

In humans edit

In January 2022, William Schaffner, professor of infectious diseases at Vanderbilt University Medical Center, compared the contagiousness of the Omicron variant to that of the measles.[219]

On 15 December 2021, Jenny Harries, head of the UK Health Security Agency, told a parliamentary committee that the doubling time of COVID-19 in most regions of the UK was now less than two days despite the country's high vaccination rate. She said that the Omicron variant of COVID-19 is "probably the most significant threat since the start of the pandemic", and that the number of cases in the next few days would be "quite staggering compared to the rate of growth that we've seen in cases for previous variants".[220]

A 2021 study suggested that mutations that promote breakthrough infections or antibody-resistance "like those in Omicron" could be a new mechanism for viral evolution success of SARS-CoV-2 and that such may become a dominating mechanism of its evolution.[221] A preprint supports such an explanation of Omicron's spread, suggesting that it "primarily can be ascribed to the immune evasiveness rather than an inherent increase in the basic transmissibility".[222][223] Studies showed the variant to escape the majority of existing SARS-CoV-2 neutralizing antibodies, including those in sera from vaccinated and convalescent individuals.[224][225][226][227] Nevertheless, existing vaccines were expected to protect against severe illness, hospitalizations, and deaths due to Omicron[228] and, on an individual level, the Omicron variant is milder than earlier variants that evolved when the antibody/vaccination share was lower than it was when Omicron emerged.[229]

In contrast to other investigated variants, Omicron showed substantial, population-level, evasion of immunity from prior infection as well as a higher ability to evade immunity induced by vaccines.[230]

Later research found that the spread of Omicron likely contributed to significant natural immunity to reinfection.[231]

In non-human animals edit

In February 2022, the first confirmed case infecting a wild animal was confirmed by researchers at Pennsylvania State University in white-tailed deer in Staten Island, N.Y.[232]

Surfaces edit

Although transmission via fomites is rare, preliminary data indicate that the variant lasts for 194 hours on plastic surfaces and 21 hours on skin, compared with just 56 and 7 hours, respectively, for the original strain.[233][234]

Vaccine effectiveness edit

Pfizer-BioNTech (BNT162b2) and Moderna (mRNA-1273) mRNA vaccines provide reduced protection against asymptomatic disease but do reduce the risk of serious illness.[235][236][237] On 22 December 2021, the Imperial College COVID-19 Response Team reported an about 41% (95% CI, 3745%) lower risk of a hospitalization requiring a stay of at least 1 night compared to the Delta variant, and that the data suggested that recipients of 2 doses of the Pfizer–BioNTech, the Moderna or the Oxford–AstraZeneca vaccine were substantially protected from hospitalization.[238] In January 2022, results from Israel suggested that a fourth dose is only partially effective against Omicron. Many cases of infection broke through, albeit "a bit less than in the control group", even though trial participants had higher antibody levels after the fourth dose.[239] On 23 December 2021, Nature indicates that, though Omicron likely weakens vaccine protection, reasonable effectiveness against Omicron may be maintained with currently available vaccination and boosting approaches.[240][241]

In December, studies, some of which using large nationwide datasets from either Israel and Denmark, found that vaccine effectiveness of multiple common two-dosed COVID-19 vaccines is substantially lower against the Omicron variant than for other common variants including the Delta variant, and that a new (often a third) dose – a booster dose – is needed and effective, as it substantially reduces deaths from the disease compared to cohorts who received no booster but two doses.[242][243][244][245][246][247]

Vaccines continue to be recommended for Omicron and its subvariants. Professor Paul Morgan, immunologist at Cardiff University said, "I think a blunting rather than a complete loss [of immunity] is the most likely outcome. The virus can't possibly lose every single epitope on its surface, because if it did that spike protein couldn't work any more. So, while some of the antibodies and T cell clones made against earlier versions of the virus, or against the vaccines may not be effective, there will be others, which will remain effective. (...) If half, or two-thirds, or whatever it is, of the immune response is not going to be effective, and you're left with the residual half, then the more boosted that is the better."[248] Professor Francois Balloux of the Genetics Institute at University College London said, "From what we have learned so far, we can be fairly confident that – compared with other variants – Omicron tends to be better able to reinfect people who have been previously infected and received some protection against COVID-19. That is pretty clear and was anticipated from the mutational changes we have pinpointed in its protein structure. These make it more difficult for antibodies to neutralise the virus."[249]

BA.1 and BA.2 edit

A January 2022 study by the UK Health Security Agency found that vaccines afforded similar levels of protection against symptomatic disease by BA.1 and BA.2, and in both it was considerably higher after two doses and a booster than two doses without booster,[250][251] though because of the gradually waning effect of vaccines, further booster vaccination may later be necessary.[170]

BA.4 and BA.5 edit

In May 2022, a preprint indicated Omicron subvariants BA.4 and BA.5 could cause a large share of COVID-19 reinfections, beyond the increase of reinfections caused by the Omicron lineage, even for people who were infected by Omicron BA.1 due to increases in immune evasion, especially for the unvaccinated. However, the observed escape of BA.4 and BA.5 from immunity by a BA.1 infection is more moderate than of BA.1 against studied prior cases of immunity (such as immunity from specific vaccines).[252][253]

Immunity from an Omicron infection for unvaccinated and previously uninfected was found to be weak "against non-Omicron variants",[254] albeit at the time Omicron is, by a large margin, the dominant variant in sequenced human cases.[255]

BQ.1 and BQ.1.1 edit

Subvariants BQ.1 and BQ.1.1 were found in late 2022 to be better at escaping first and booster vaccines than previous variants, and to have further reduced the effectiveness of monoclonal antibody treatments.[256]

Vaccine adjustments edit

In June 2022, Pfizer and Moderna developed bivalent vaccines to protect against the SARS-CoV-2 wild-type and the Omicron variant. The bivalent vaccines are well-tolerated and offer immunity to Omicron superior to previous mRNA vaccines.[257] In September 2022, the United States Food and Drug Administration (FDA) authorized the bivalent vaccines for use in the US.[258][259][260]

In June 2023, the FDA advised manufacturers that the 2023–2024 formulation of the COVID-19 vaccines for use in the US be updated to be a monovalent COVID-19 vaccine using the XBB.1.5 lineage of the Omicron variant.[261][262]

Signs and symptoms edit

Loss of taste and smell seem to be uncommon compared to other strains.[5][6] A unique reported symptom of the Omicron variant is night sweats,[7][263] particularly with the BA.5 subvariant.[264][265] A study performed between 1 and 7 December 2021 by the Center for Disease Control found that: "The most commonly reported symptoms [were] cough, fatigue, and congestion or runny nose" making it difficult to distinguish from a less damaging variant or another virus.[266] Research published in London on 25 December 2021 suggested the most frequent symptoms stated by users of the Zoe Covid app were "a runny nose, headaches, fatigue, sneezing and sore throats."[4]

A British Omicron case-control observational study until March 2022 showed a reduction in odds of long COVID with the Omicron variant versus the Delta variant of 0·24–0·5 depending on age and time since vaccination.[267]

Virulence edit

As of 6 January 2022, Omicron multiplied around 70 times faster than the Delta variant in the bronchi (lung airways) but evidence suggested it is less severe than previous variants, especially compared to Delta,[268][229] since it might be less able to penetrate deep lung tissue.[269] As of January 2022, in southern California infections were 91 percent less fatal than the delta variant, with 51 percent less risk of hospitalization.[270] However, the estimated difference in the intrinsic risk of hospitalization in England largely decreased to 0–30 percent, when reinfections were excluded.[271]

As of 21 January 2022 the risk of hospitalization was the same in BA.1 and BA.2 based on reviews from Denmark, India, South Africa and the United Kingdom.[272][149][165][273] Norwegian studies showed that the amount of virus in the upper airways was similar in those infected with BA.1 and BA.2.[167]

Diagnosis edit

As of November 2021, the chance of detecting an Omicron case particularly depended on a country's sequencing rate, with South Africa sequencing far more samples than any other country in Africa, but at a considerably lower rate than most Western nations.[274][275] Sequencing the virus from a sample can take weeks limiting the early availability of data.[276]

In January 2022 the medicine and therapeutic regulatory agency Therapeutic Goods Administration (TGA) of the Australian Government had only tested one of their 23 approved COVID-19 rapid antigen tests (RAT) to verify it detected Omicron.[277] The TGA later updated their approved list to show that all RATs which detected other variants could detect Omicron infections.[278] In June 2022, the German federal Paul-Ehrlich-Institute published their findings, that most RATs detected the Omicron Variant.[279]

PCR testing edit

In December 2021, the US FDA published guidelines on how PCR tests would be affected by Omicron.[280] Tests that detect multiple gene targets were to continue to identify the testee as positive for COVID-19. S-gene dropout or target failure was proposed as a shorthand way of differentiating Omicron from Delta. besides sequencing and genotyping.[281]

As of December 2021, Denmark and Norway have regarded cases found by their variant qPCR test, which is relatively fast and checks several genes,[282] as sufficient for counting it as Omicron, before full sequencing.[283][284]

BA.1 and BA.2 differences edit

As of 7 December 2021 it was known that BA.2, unlike BA.1, lacks the characteristic S-gene target failure (SGTF) causing deletion (Δ69-70), by which many qPCR tests have been able to rapidly detect a case as an Omicron (or Alpha) variant, from the previously dominant Delta variant.[285][286] Thus, countries which primarily rely on SGTF for detection may overlook BA.2,[285] and British authorities consider SGTF alone as insufficient for monitoring the spread of Omicron.[272] This has resulted in it having been nicknamed 'Stealth Omicron',[272] but because BA.2 still can be separated from other variants through normal full sequencing, or checks of certain other mutations, the nickname is not quite accurate.[140][287] As of January 2022, some countries, such as Denmark and Japan, have been using a variant qPCR which tests for several mutations, including L452R.[282][161] It can also distinguish Delta, which has L452R,[288] and all Omicron subvariants, which do not have L452R.[289][147] As Omicron became dominant and the Delta variant became rare in early 2022, the SGTF mutation that had made Delta and BA.2 similar in qPCR tests was found to be useful for separating BA.1 and BA.2 from each other.[290]

Treatment edit

As of 28 November 2021, Corticosteroids such as dexamethasone and IL6 receptor blockers such as tocilizumab (Actemra) were known to be effective for managing patients with the earlier strains of severe COVID-19 but the impact on the effectiveness of other treatments was being assessed.[291][292]

Relating to monoclonal antibodies (mAbs) treatments, similar testing and research is ongoing. Preclinical data on in vitro pseudotyped virus data demonstrate that some mAbs designed to use highly conserved epitopes retain neutralizing activity against key mutations of Omicron substitutions.[293] Similar results are confirmed by cryo-electron microscopy and X-ray data, also providing the structural approach and molecular basis for the evasion of humoral immunity exhibited by Omicron antigenic shift as well as the importance of targeting conserved epitopes for vaccine and therapeutics design. While 7 clinical mAbs or mAb cocktails experienced loss of neutralizing activity of 1-2 orders of magnitude or greater relative to the prototypic virus, the S309 mAb, the parent mAb of sotrovimab, neutralized Omicron with only 2-3-fold reduced potency.[294]

As of December 2021, most monoclonal antibodies had lost in vitro neutralizing activity against Omicron, with only 3 out of 29 mAbs examined in another study retaining unaltered potency. Furthermore, a fraction of broadly neutralizing sarbecovirus mAbs neutralized Omicron through recognition of antigenic sites outside the RBM, including sotrovimab (VIR-7831), S2X259 and S2H97.[295] However, sotrovimab was not fully active against the BA.2 Omicron sublineage, and in March 2022 the office of the U.S. ASPR stopped distributing the antibody treatment to states where BA.2 was dominant.[296] February 2022 data suggested Omicron caused significant humoral immune evasion, while neutralizing antibodies targeting the sarbecovirus conserved region remained most effective.[297]

Epidemiology edit

On 26 November 2021, the South African National Institute for Communicable Diseases announced that 30,904 COVID-19-tests (in one day) detected 2,828 new COVID-19 infections (a 9.2% positivity rate).[298] One week later, on 3 December 2021, the NICD announced that 65,990 COVID-19 tests had found 16,055 new infections (5.7 times as many as seven days before; positive rate 24.3%) and that 72 percent of them were found in Gauteng.[299][300] This province of South Africa is densely populated at about 850 inhabitants per km2. Gauteng's capital Johannesburg is a megacity (about 5.5 million inhabitants in the city itself plus 9.5 million in the urban region).[citation needed]

In November 2021, the transmissibility of the Omicron variant, as compared to the Delta variant or other variants of the COVID-19 virus, was still uncertain.[291] Omicron is frequently able to infect previously COVID-19-positive people.[301][302]

It has been estimated the Omicron variant diverged in late September or early October 2021, based on Omicron genome comparisons.[303] Sequencing data suggests that Omicron had become the dominant variant in South Africa by November 2021, the same month where it had been first identified in the country.[304][305]

Phylogeny suggests a recent emergence. Data from South Africa suggests that Omicron has a pronounced growth advantage there. However, this may be due to transmissibility or immune escape related, or both."[306] Also the serial interval plays a role in the growth.

Detectable changes in levels of COVID-19 in wastewater samples from South Africa's Gauteng province were seen as early as 17–23 October (week 42).[307] The National Institute for Communicable Diseases reports that children under the age of 2 make up 10% of total hospital admissions in the Omicron point of discovery Tshwane in South Africa.[308] Data on the S gene target failure (SGTF) of sampled cases in South Africa indicates a growth of 21% per day relative to Delta, generating an increased reproduction number by a factor of 2.4.[a] Omicron became the majority strain in South Africa around 10 November.[309][310] Another analysis showed 32% growth per day in Gauteng, South Africa, having become dominant there around 6 November.[311]

In the UK, the logarithmic growth rate of Omicron-associated S gene target failure (SGTF) cases over S gene target positive (SGTP) cases was estimated at 0.37 per day,[b] which is exceptionally high.[312] Furthermore, by 14 December it appears to have become the most dominant strain.[c][313] Without presuming behavior change in response to the variant, a million infections per day by 24 December are projected for a 2.5 days doubling time.[d][281] In Denmark, the growth rate has been roughly similar with a doubling time of about 2–3 days, it having become the most prevalent strain on 17 December.[314][315][316] Switzerland is not far behind.[317] In Germany Omicron became the most prevalent variant on 1 January.[318] In Scotland, Omicron apparently became the most prevalent variant on 17 December.[319][320] In the Canadian province of Ontario it became the most prevalent strain on 13 December.[321] In the US, the variant appears to have become the most prevalent strain on 18 December, growing at 0.24 per day.[322] In Portugal, Omicron had reached 61.5% of cases on 22 December.[323] In Belgium, the strain has become the most prevalent on 25 December,[324] and in the Netherlands on 28 December.[325] In Italy, it had reached 28% of cases on 20 December and was doubling every two days,[326] while it became the dominant variant in Norway on 25 December.[327] In France, it made up about 15% of COVID-19 cases in mid-December, but around 27 December it had increased to more than 60%.[328][329] Researchers recommend sampling at least 5% of COVID-19 patient samples in order to detect Omicron or other emerging variants.[330]

During January 2022, in Denmark the BA.2 variant grew at ~0.10 per day (+11% per day) as a ratio to BA.1 (the legacy Omicron variant), and became the dominant strain in week 2, 2022.[164] In the United Kingdom, the BA.2 variant was growing at ~0.11 per day (+12% per day) as a ratio to BA.1.[331]

On 13 January 2022, the BBC reported that the hospitalization rate was higher in the US and Canada than in Europe and South Africa. This was attributed to a combination of a greater number of elderly people than in South Africa, greater prevalence of comorbidities such as hypertension and obesity than in Europe, higher indoor transmission due to the winter, lower vaccination rate in the US than in Europe and Canada, and a possible still high prevalence of the Delta variant, which more often leads to hospitalization.[332]

Reported cases edit

Confirmed and suspected cases by country and territory
Country/Territory Confirmed cases (PANGOLIN)[333]
as of 5 May, 2022
Confirmed cases (GISAID)[334]
as of July 29, 2022
Confirmed cases (other sources)
As of 24 June 2022
Suspected cases
  United States 999,565 1,431,772 62,480[335]As of January 8, 2022
  United Kingdom 999,565 1,253,700 246,780[336] 600,041[336]
  Germany 207,407 365,837 268,661[337]
  Austria 6,809 57,379 290,378[338][339]
  Denmark 196,746 264,998 66,563[340]
  France 83,564 184,880 5,591[341]
  Canada 73,584 147,223 174,248[342]
  Japan 67,203 153,110 12,453[343]
  India 37,542 81 017 8,209[344][345]
  Australia 33,905 80,013 11,071[346]
  Norway 14,729 24,529 45,296[283]
  Thailand 6,778 12,811 5,397[347]
  Indonesia 9,761 12,028 3,779[348]
  Singapore 4,543 7,300 4,322[349][350][351][352]
  Estonia 1,982 3,778 3,857[353][354][355]
  Israel 22,164 60,435 1,741[356][357] 861[356]
  South Africa 9,631 16,451 1,095[358] 19,070[359]
  South Korea 7,731 27,705 1,318[360]
  Spain 24,607 31,992 51[337][361]
  Belgium 26,448 30,865 121[338][361]
  Sweden 38,397 42,525 53.760[362]
   Switzerland 30,034 32,635 19,269[338][363]
  Argentina 2,228 2,583 455[364][365] 80[366]
  Botswana 931 1,594 23[367]
  Netherlands 24,381 26,601 123[368][361]
  Ireland 24,654 29,518 29,576[369]
  Gibraltar 112 122 24[370]
  Iceland 84[371]
  Italy 23,707 27,292 84[372]
  Chile 4,097 4,572 684[373][374][375]
  Portugal 7,683 8,870 69[376][361] 6[377][338]
  Morocco 128 138 76[378] 246[378]
  Zimbabwe 185 219 50[379]
  Ghana 441 605 33[367]
  Brazil 27,787 32,224 203[380]
  Finland 4,029 5,239 523[381][382]
  Cyprus 31[383][384]
  Kenya 1,653 2,329 27[385]
  Russia 1,273 1,738 8,239[386]
  Cayman Islands 44[387] 59[387]
  Uganda 12 38 25[388][389]
  Mexico 12,736 13,678 1[390]
  New Zealand 3,169 3,739 116[391]
  Namibia 125 213 18[392]
  Hong Kong 1,432 3,526 102[393][394]
  Senegal 14 229 3[395]
  Mozambique 133 176 2[396] 2[335]
  Greece 3,268 3,276 17[338][397]
  Bermuda 24 144[398][399]
  Latvia 407 407 644[400][361][401]
  Romania 4,034 4,282 25[402][403][404]
  Malaysia 5,330 7,353 245[405]
  Zambia 141 365 11[406]
  Nigeria 827 1,638 6[407]
  Czech Republic 13,264 15,147 10[338][408][361]
  Kosovo 245 262 9[409]
  Slovenia 15,684 17,106 1,418[410][361][411][412]
  Lebanon 85 107 433[413][414] 16[413]
  Reunion 2,014 2,402 2[415]
  Mauritius 763 7[335]
  Poland 31,766 33,327 1[416]
  Rwanda 70 178 6[416]
  Turkey 9,135 10,239 6[417]
  Montenegro 142 211 5[418]
  Cambodia 950 974 31[419]
  Peru 5,653 5,960 10,032[420]
  Jordan 83 83 832[421]
  China 96 96 4[422][423][424]
  Cuba 92[425][426][427]
  Croatia 10,379 11,742 3[338]
  Egypt 15 40 3[416]
  Malawi 133 166 3[428]
  Palestinian Territory 5 9 126[429][430]
  Taiwan 34 34 89[431]
  Lithuania 7,063 9,136 2[432]
  Colombia 1,629 3,816 3[433]
  Slovakia 13,501 15,625 3[434]
  Trinidad and Tobago 291 499 1[435]
  Puerto Rico 3,166 3,558 1[436]
  Fiji 2[437]
    Nepal 255 349 2[438]
  Myanmar 25 28 4[439]
  Philippines 1,281 1,549 535[440][441][442][443][444][445]
  Northern Cyprus 9[446]
  Bangladesh 690 998 10[447]
  Liechtenstein 246 736 1[448] 3[335]
  Hungary 28 28 61[449][361][450]
  Oman 71 85 2[451]
  Pakistan 359 463 75[452][453]
  Sri Lanka 626 927 1[454]
  Georgia (country) 718 822 600[455]
  Algeria 61 73 1[416]
  Bahrain 1[456]
  Ecuador 1,177 1,561 1[457]
  Kuwait 54 72 1[458]
  Luxembourg 4,031 11,149 1[338]
  Maldives 281 5[459][460]
  Sierra Leone 1 1[461]
  Saudi Arabia 28 30 1[462]
  Tunisia 51 52 1[463]
  United Arab Emirates 1 1[464]
  Iran 595 682 467[465]
  Ukraine 73 99 1[466]
  Panama 821 822 1[467]
  Costa Rica 1,430 1,529 1[468]
  Aruba 61 61 1[469]
  North Macedonia 46 47 9[470][471]
  Vietnam 1,085 1,790 108[472]
  Brunei 1,163 1,253 8[473]
  Malta 138 162 2[474]
  Venezuela 60 62 7[475]
  French Guiana 366 20[476]
  Republic of the Congo 50 78 1[477]
  Qatar 267 290 4[478]
  Paraguay 122 139 3[479]
  Burkina Faso 17 2[480]
  Curacao 482 487 1[481]
  Saint Kitts and Nevis 16 2[482]
  Libya 2[483]
  Albania 1 1 1[484]
  Barbados 1 7 1[485]
  Saint Vincent and the Grenadines 62 1[486]
  Dominican Republic 69 73 1[487]
  Jamaica 443 622 1[488]
  Serbia 81 81 1[489]
  Tanzania 2 3 1[490]
  Togo 5[491]
  Belarus 71 4[492]
  Bosnia and Herzegovina 118 122 10[493]
  Angola 25 37 16[494]
  Democratic Republic of the Congo 34 204 1[495]
  Bulgaria 2,516 2,520 12[496]
  Mayotte 123 130 1[497]
  Martinique 593 1[498]
  Gambia 30 155 26[499]
  Seychelles 235 464[500]
  Saint Martin 224 240 2[501]
  Laos 1[502]
  Iraq 36 103 5[503]
  Mauritania 14[504]
  South Sudan 28 28 41[505]
  Ivory Coast 41 60 78[506]
  Cape Verde 152 175[507]
  Antigua and Barbuda 36 1[508]
  Gabon 1[509]
  Bolivia 2 7 1[510]
  Moldova 287 314 29[511]
  Kazakhstan 8 8 8[512]
  Guadeloupe 264 300 1[513]
  Azerbaijan 12 12 12[514]
  Suriname 81 96 146[500]
  Sint Maarten 479 753[500]
  British Virgin Islands 20 26 39[500]
  Mali 1 2
  Anguilla 20 24 30[500]
  Bonaire 400 692[500]
  Bhutan 14[515]
  Papua New Guinea 379 565 1[516]
  Mongolia 133 133 12[517]
  Antarctica 24[518]
  Uzbekistan 1[519]
  Saint Lucia 1 9 54[500]
  Burundi 1 28[500]
  American Samoa 35 84[500]
  Armenia 4 16 17[500]
  Guinea 48 167 159[500]
  Guam 168 274 348[500]
  Belize 223 240 441[500]
  Eswatini 124 133
  Djibouti 306 308 337[500]
 World total (170 countries and territories) 2,986,573 3,517,102 1,168,383 620,384


See also edit

Notes edit

  1. ^ With a presumed identical person-to-person serial interval of loge(2.4)/0.21 ~ 4.2 days, or a distribution thereof to the same effect.
  2. ^ Logarithmic growth rate of 0.37/day means that the log odds loge(SGTF/SGTP) is increasing by 0.37 in a day. So SGTF/SGTP was increasing by a multiplicative factor of exp(0.37) ~ 1.45. This is substantially higher than a naive increase to 100%+37%. The difference is mathematically due to compound growth within the day, which does not imply that epidemically people are already infectious within a day. Rather, simplified (non-delay) differential equations are used for convenience for the modeling. This also indicates a doubling time of loge(2)/(0.37/day) ~ 1. days for the Omicron to Delta prevalence ratio.
  3. ^ Referring to ref 12 in the reference, where the x-axis is crossed at 14 December.
  4. ^ A doubling time of 2.5 days corresponds to an exponential growth rate of ln(2)/(2.5 days) ~ 0.28/day. Direct comparison to the logistic growth rate needs to take the growth/decline of Delta into account.

References edit

  1. ^ a b c Yadav PD, Gupta N, Potdar V, Mohandas S, Sahay RR, Sarkale P, et al. (January 2022). An in vitro and in vivo approach for the isolation of Omicron variant from human clinical specimens. pp. 2022–01.02.474750. doi:10.1101/2022.01.02.474750. from the original on 16 January 2022. Retrieved 16 January 2022.
  2. ^ a b Padin M (17 January 2022). "Feeling light-headed may be an early indication you have Omicron Covid variant". Daily Mirror. from the original on 28 January 2022. Retrieved 30 January 2022.
  3. ^ Poudel S, Ishak A, Perez-Fernandez J, Garcia E, León-Figueroa DA, Romaní L, et al. (December 2021). "Highly mutated SARS-CoV-2 Omicron variant sparks significant concern among global experts – What is known so far?". Travel Medicine and Infectious Disease. 45: 102234. doi:10.1016/j.tmaid.2021.102234. PMC 8666662. PMID 34896326.
  4. ^ a b c d Adams R (24 December 2021). "Omicron's cold-like symptoms mean UK guidance 'needs urgent update'". The Guardian. from the original on 25 December 2021.
  5. ^ a b "Omicron Symptoms: Here's How They Differ From Other Variants". NBC Chicago. 7 January 2022. from the original on 24 January 2022. Retrieved 30 January 2022.
  6. ^ a b Slater, Jack (23 January 2022). "Is a change to your taste or smell a sign of Omicron?". Metro. from the original on 26 January 2022. Retrieved 30 January 2022.
  7. ^ a b Scribner H (21 December 2021). "Doctor reveals new nightly omicron variant symptom". Deseret News. from the original on 2 January 2022. Retrieved 1 January 2022.
  8. ^ "Does Omicron cause less damage to the lungs?". medicalnewstoday.com. 14 January 2022. Retrieved 22 August 2023.
  9. ^ Murrison P (18 January 2022). "Omicron symptoms: Three distinctive rashes to watch for". Express.co.uk. from the original on 12 January 2022. Retrieved 30 January 2022.
  10. ^ a b c Quarleri J, Galvan V, Delpino MV (February 2022). "Omicron variant of the SARS-CoV-2: a quest to define the consequences of its high mutational load". GeroScience. 44 (1): 53–56. doi:10.1007/s11357-021-00500-4. PMC 8683309. PMID 34921354.
  11. ^ Gowrisankar A, Priyanka TM, Banerjee S (10 January 2022). "Omicron: a mysterious variant of concern". European Physical Journal Plus. 137 (1): 100. Bibcode:2022EPJP..137..100G. doi:10.1140/epjp/s13360-021-02321-y. PMC 8743750. PMID 35036269.
  12. ^ a b Vitiello A, Ferrara F, Auti AM, Di Domenico M, Boccellino M (July 2022). "Advances in the Omicron variant development". Journal of Internal Medicine. 292 (1): 81–90. doi:10.1111/joim.13478. PMC 9115048. PMID 35289434.
  13. ^ a b Yao L, Zhu KL, Jiang XL, Wang XJ, Zhan BD, Gao HX, et al. (June 2022). "Omicron subvariants escape antibodies elicited by vaccination and BA.2.2 infection". The Lancet. Infectious Diseases. 22 (8): 1116–1117. doi:10.1016/s1473-3099(22)00410-8. PMC 9212811. PMID 35738299.
  14. ^ Ahmed SF, Quadeer AA, McKay MR (January 2022). "SARS-CoV-2 T Cell Responses Elicited by COVID-19 Vaccines or Infection Are Expected to Remain Robust against Omicron". Viruses. 14 (1): 79. doi:10.3390/v14010079. PMC 8781795. PMID 35062283.
  15. ^ Al Jurdi A, Gassen RB, Borges TJ, Lape IT, Morena L, Efe O, et al. (June 2022). "Suboptimal antibody response against SARS-CoV-2 Omicron variant after third dose of mRNA vaccine in kidney transplant recipients". pp. 1282–1286. medRxiv 10.1101/2022.01.03.22268649v1.
  16. ^ Altarawneh HN, Chemaitelly H, Ayoub HH, Tang P, Hasan MR, Yassine HM, et al. (July 2022). "Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections". The New England Journal of Medicine. 387 (1): 21–34. doi:10.1056/NEJMoa2203965. PMC 9258753. PMID 35704396. S2CID 249677809.
  17. ^ Nemet I, Kliker L, Lustig Y, Zuckerman N, Erster O, Cohen C, et al. (February 2022). "Third BNT162b2 Vaccination Neutralization of SARS-CoV-2 Omicron Infection". The New England Journal of Medicine. 386 (5): 492–494. doi:10.1056/NEJMc2119358. PMC 8823651. PMID 34965337.
  18. ^ Cao Y, Yisimayi A, Jian F, Song W, Xiao T, Wang L, et al. (June 2022). "BA.2.12.1, BA.4 and BA.5 escape antibodies elicited by Omicron infection". Nature. 608 (7923): 593–602. Bibcode:2022Natur.608..593C. doi:10.1038/s41586-022-04980-y. PMC 9385493. PMID 35714668.
  19. ^ Hachmann NP, Miller J, Collier AY, Ventura JD, Yu J, Rowe M, et al. (July 2022). "Neutralization Escape by SARS-CoV-2 Omicron Subvariants BA.2.12.1, BA.4, and BA.5". The New England Journal of Medicine. 387 (1): 86–88. doi:10.1056/NEJMc2206576. PMC 9258748. PMID 35731894. S2CID 249956777.
  20. ^ Patel V (27 November 2021). "How Omicron, the New Covid-19 Variant, Got Its Name". The New York Times. ISSN 0362-4331. from the original on 28 November 2021. Retrieved 28 November 2021.
  21. ^ Tcholakian D (15 December 2021). "'Omni is everywhere': why do so many people struggle to say Omicron?". The Guardian. from the original on 23 December 2021. Retrieved 23 December 2021.
  22. ^ Zimmer B (2 December 2021). "'Omicron': Greek's 'Little O' Will Loom Larger Now". Wall Street Journal. ISSN 0099-9660. from the original on 3 December 2021. Retrieved 23 December 2021. President Joe Biden stumbled over the pronunciation in a press conference on Monday, calling the variant "omnicron" with an extra "n" sound. It has also been frequently misspelled that way online. The confusion is understandable, since we're more familiar with words that have the Latin prefix "omni-" meaning "all," as in "omnipresent" or "omnivore."
  23. ^ "In focus". gisaid.org. GISAID. 28 November 2021. from the original on 21 January 2021. Retrieved 28 November 2021. The unique mix of spike amino acid changes in Omicron GR/484A (B.1.1.529) is of interest as it comprises several that were previously known to affect receptor binding and antibody escape.
  24. ^ a b "Variant: 21K (Omicron)". covariants.org. CoVariants. 28 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021. Variant 21K (Omicron) appears to have arisen in November 2021, possibly in South Africa.
  25. ^ a b Viana R, Moyo S, Amoako DG, Tegally H, Scheepers C, Althaus CL, et al. (March 2022). "Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in southern Africa". Nature. 603 (7902): 679–686. Bibcode:2022Natur.603..679V. doi:10.1038/s41586-022-04411-y. PMC 8942855. PMID 35042229.
  26. ^ Dyer O (December 2021). "Covid-19: South Africa's surge in cases deepens alarm over omicron variant". BMJ. 375: n3013. doi:10.1136/bmj.n3013. PMID 34862184. S2CID 244842008.
  27. ^ a b Gu H, Krishnan P, Ng DY, Chang LD, Liu GY, Cheng SS, et al. (February 2022). "Probable Transmission of SARS-CoV-2 Omicron Variant in Quarantine Hotel, Hong Kong, China, November 2021". Emerging Infectious Diseases. 28 (2): 460–462. doi:10.3201/eid2802.212422. PMC 8798678. PMID 34860154.
  28. ^ a b Planas D, Saunders N, Maes P, Guivel-Benhassine F, Planchais C, Buchrieser J, et al. (February 2022). "Considerable escape of SARS-CoV-2 Omicron to antibody neutralization". Nature. 602 (7898): 671–675. Bibcode:2022Natur.602..671P. doi:10.1038/s41586-021-04389-z. PMID 35016199. S2CID 256823009.
  29. ^ a b Saxena SK, Kumar S, Ansari S, Paweska JT, Maurya VK, Tripathi AK, Abdel-Moneim AS (May 2022). "Transmission dynamics and mutational prevalence of the novel Severe acute respiratory syndrome coronavirus-2 Omicron Variant of Concern". Journal of Medical Virology. 94 (5): 2160–2166. doi:10.1002/jmv.27611. PMC 9015611. PMID 35050521.
  30. ^ a b Wei C, Shan KJ, Wang W, Zhang S, Huan Q, Qian W (December 2021). "Evidence for a mouse origin of the SARS-CoV-2 Omicron variant". Journal of Genetics and Genomics = Yi Chuan Xue Bao. 48 (12): 1111–1121. doi:10.1016/j.jgg.2021.12.003. PMC 8702434. PMID 34954396.
  31. ^ a b Alkhatib M, Salpini R, Carioti L, Ambrosio FA, D'Anna S, Duca L, et al. (April 2022). Perez DR (ed.). "Update on SARS-CoV-2 Omicron Variant of Concern and Its Peculiar Mutational Profile". Microbiology Spectrum. 10 (2): e0273221. doi:10.1128/spectrum.02732-21. PMC 9045195. PMID 35352942.
  32. ^ a b c Tarcsai KR, Corolciuc O, Tordai A, Ongrádi J (June 2022). "SARS-CoV-2 infection in HIV-infected patients: potential role in the high mutational load of the Omicron variant emerging in South Africa". GeroScience. 44 (5): 2337–2345. doi:10.1007/s11357-022-00603-6. PMC 9225796. PMID 35739343.
  33. ^ "The mystery of where omicron came from — and why it matters". NPR. 1 December 2021. from the original on 9 December 2021. Retrieved 8 December 2021.
  34. ^ Zungu N, Mabaso M, Ramlagan S, Simbayi L, Moyo S, Shisana O, et al. (May 2022). "Is There Risk Compensation among HIV Infected Youth and Adults 15 Years and Older on Antiretroviral Treatment in South Africa? Findings from the 2017 National HIV Prevalence, Incidence, Behaviour and Communication Survey". International Journal of Environmental Research and Public Health. 19 (10): 6156. doi:10.3390/ijerph19106156. PMC 9141949. PMID 35627693.
  35. ^ Fischer, Carlo; et al. (2022). "Gradual emergence followed by exponential spread of the SARS-CoV-2 Omicron variant in Africa". Science. 378 (6623): eadd8737. doi:10.1126/science.add8737. PMID 36454863. S2CID 254150265.
  36. ^ Mallapaty, Smriti (6 December 2022). "Surprising Omicron origins study comes under scrutiny". Nature. 612 (7940): 387–388. Bibcode:2022Natur.612..387M. doi:10.1038/d41586-022-04357-1. PMID 36474049. S2CID 254402519.
  37. ^ "Study on the origins of Omicron retracted". www.charite.de. 20 December 2022. Retrieved 24 December 2022. In a subsequent analysis of residual samples, they were found to be contaminated. It is no longer possible to establish the source of the contamination.
  38. ^ "'We made a mistake.' Omicron origin study retracted after widespread criticism". science.org. 20 December 2022. Retrieved 24 December 2022. But Kristian Andersen [...] says the gradual evolution theory was already "off the table" before the paper was published.
  39. ^ Cowan K (29 November 2021). "Inside SA leg of Omicron variant discovery: A single test result, a missing gene, and an email". News24. from the original on 2 December 2021. Retrieved 2 December 2021.
  40. ^ a b Callaway E (December 2021). "Heavily mutated Omicron variant puts scientists on alert". Nature. 600 (7887): 21. Bibcode:2021Natur.600...21C. doi:10.1038/d41586-021-03552-w. PMID 34824381. S2CID 244660616. from the original on 26 November 2021. Retrieved 26 November 2021.
  41. ^ a b @BNODesk (26 November 2021). "Statement from Israel's health ministry reporting 1 confirmed case of new coronavirus variant B.1.1.529" (Tweet). Retrieved 26 November 2021 – via Twitter.
  42. ^ ינקו, אדיר; שומפלבי, אטילה (26 November 2021). "מחוסנת ב-3 מנות ואישה שנסעה לאילת באוטובוס: המאומתים לזן החדשt". Ynet (in Hebrew). from the original on 27 November 2021. Retrieved 28 November 2021. "4 מאומתים לווריאנט החדש התגלו בארץ, רה"מ יקיים מסיבת עיתונאים ב-14:30" translated: "4 verified for the new variant were discovered in the country, the prime minister will hold a press conference at 14:30
  43. ^ Four cases of the new COVID-19 variant recorded in Botswana 26 November 2021 at the Wayback Machine, 25 November 2021, Mmegi Online, accessed 26 November 2021
  44. ^ Kesselgruber K (27 November 2021). [Frankfurt airport: Person suspected to be infected with Omicron Variant was fully vaccinated]. Frankfurter Rundschau (in German). Archived from the original on 27 November 2021. Retrieved 27 November 2021.
  45. ^ "UK, Germany and Italy detect Omicron coronavirus variant cases". Reuters. 27 November 2021. from the original on 27 November 2021. Retrieved 27 November 2021.
  46. ^ "Coronavirus variant Omicron found in 13 positive tests so far | RIVM". www.rivm.nl. from the original on 6 December 2021. Retrieved 6 December 2021.
  47. ^ "Actuele informatie over COVID-19 | RIVM" [Current information about COVID-19 | RIVM]. www.rivm.nl (in Dutch). 4 December 2021. from the original on 6 April 2020. Retrieved 6 December 2021.
  48. ^ "61 travellers from South Africa in Netherlands positive for COVID-19 – authorities". Reuters. Amsterdam. 27 November 2021. from the original on 26 November 2021. Retrieved 27 November 2021.
  49. ^ "Travellers test positive to Omicron COVID-19 strain after arriving in Sydney from southern Africa, NSW Health says". ABC News. 28 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021.
  50. ^ "To personer er indrejst i Danmark med coronavarianten Omikron" [Two people have entered Denmark with the corona variant Omicron]. www.bt.dk (in Danish). 28 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021.
  51. ^ Ritzau A (28 November 2021). "Nu er det bekræftet: To personer smittet med Omikron rejst ind i Danmark" [Now it has been confirmed: Two people infected with Omicron traveled into Denmark]. ekstrabladet.dk (in Danish). from the original on 28 November 2021. Retrieved 28 November 2021.
  52. ^ "Austria detects suspect Omicron case as Europe battles virus surge". WION. from the original on 28 November 2021. Retrieved 28 November 2021.
  53. ^ "Omicron variant found in UK, Germany, Czech Republic". New York Post. 28 November 2021. from the original on 27 November 2021. Retrieved 28 November 2021.
  54. ^ "Canada, Netherland, Australia latest countries reporting cases of omicron COVID-19 variant". ABC13. 28 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021.
  55. ^ Perera A (29 November 2021). "COVID-positive repatriation flight arrival to the Northern Territory tests positive to Omicron variant". ABC News. from the original on 29 November 2021. Retrieved 29 November 2021.
  56. ^ Nguyen K (29 November 2021). "NSW Health confirms two more Omicron COVID-19 cases in travellers from southern Africa". ABC News. from the original on 29 November 2021. Retrieved 29 November 2021.
  57. ^ "Live updates: Omicron variant". Cable News Network. 29 November 2021. from the original on 30 November 2021. Retrieved 29 November 2021.
  58. ^ "Första fallet av omikron upptäckt i Sverige" [The first case of omicron detection in Sweden]. www.aftonbladet.se (in Swedish). 29 November 2021. from the original on 30 November 2021. Retrieved 29 November 2021.
  59. ^ "Spain detects first Omicron case, COVID-19 infections rise". Reuters. 29 November 2021. from the original on 30 November 2021. Retrieved 30 November 2021.
  60. ^ "Omicron variant found in two previous test samples | RIVM". www.rivm.nl. from the original on 4 December 2021. Retrieved 6 December 2021.
  61. ^ "NSW records fifth case of Omicron COVID-19 variant as two more potential infections investigated". ABC News. 30 November 2021. from the original on 30 November 2021. Retrieved 30 November 2021.
  62. ^ "Japan's first Omicron case may help portray PM Kishida as decisive". Reuters. 30 November 2021. from the original on 30 November 2021. Retrieved 30 November 2021.
  63. ^ "Two Israeli doctors test positive for Omicron COVID variant". The Jerusalem Post. 30 November 2021. from the original on 31 December 2021. Retrieved 30 November 2021.
  64. ^ "SP confirma terceiro caso da variante ômicron" [SP confirms third case of ômicron variant]. g1 (in Brazilian Portuguese). 1 December 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  65. ^ "O que se sabe sobre os primeiros casos confirmados da variante Ômicron no Brasil" [What is known about the first confirmed cases of the Ômicron variant in Brazil]. CNN Brasil (in Brazilian Portuguese). 30 November 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  66. ^ "Passa para 6 o número de casos suspeitos da variante Ômicron investigados no Brasil" [The number of suspected cases of the Ômicron variant investigated in Brazil goes to 6]. CNN Brasil (in Brazilian Portuguese). 30 November 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  67. ^ "Germany: Leipzig reports first Omicron variant case with no travel history". Free Press Journal. from the original on 1 December 2021. Retrieved 1 December 2021.
  68. ^ Dahir A, Ezeamalu B, Pérez-Peña R (1 December 2021). "Ghana and Nigeria are the latest African countries to detect the Omicron variant". The New York Times. from the original on 2 December 2021. Retrieved 2 December 2021.
  69. ^ "Nigeria confirms first cases of Omicron among travellers from South Africa". Reuters. 1 December 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  70. ^ Graff A (1 December 2021). "First case of omicron in US identified in San Francisco". San Francisco Chronicle. from the original on 1 December 2021. Retrieved 1 December 2021.
  71. ^ Stark K, Rodriguez JF, Dillon RM (1 December 2021). "First U.S. Case of Omicron Variant Found in San Francisco Resident". San Francisco: KQED. from the original on 1 December 2021. Retrieved 1 December 2021.
  72. ^ O'Donnell D (1 December 2021). "Case of Omicron variant confirmed in Ireland". RTÉ News and Current Affairs. from the original on 3 December 2021. Retrieved 12 December 2021.
  73. ^ "South Korea reports five Omicron cases on flight from Nigeria". Reuters. 1 December 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  74. ^ "Dutch say 14 air passengers from S. Africa with Omicron were vaccinated". Reuters. 2 December 2021. from the original on 2 December 2021. Retrieved 2 December 2021.
  75. ^ "Number of confirmed omicron cases as of 3 December". Folkehelseinstituttet. 4 December 2021. from the original on 4 December 2021. Retrieved 4 December 2021.
  76. ^ "France now has 25 Omicron Covid variant cases – minister". Reuters. 6 December 2021. from the original on 6 December 2021. Retrieved 7 December 2021.
  77. ^ "Omicron sudah sampai ke Malaysia". Malaysiakini. 3 December 2021. from the original on 3 December 2021. Retrieved 8 December 2021.
  78. ^ "Namibia detects Omicron coronavirus variant in 18 of 19 samples". Reuters. 6 December 2021. from the original on 6 December 2021. Retrieved 7 December 2021.
  79. ^ "Fijians test positive for Omicron variant – Govt". RNZ. 7 December 2021. from the original on 6 December 2021. Retrieved 8 December 2021.
  80. ^ "Africa accounts for 46% of reported cases of Omicron, WHO official says". Reuters. 9 December 2021. from the original on 10 December 2021. Retrieved 9 December 2021.
  81. ^ "Covid: First UK death recorded with Omicron variant". BBC News. 13 December 2021. from the original on 20 December 2021. Retrieved 13 December 2021.
  82. ^ "First Omicron case detected in New Zealand". Ministry of Healfh. 16 December 2021. from the original on 20 December 2021. Retrieved 16 December 2021.
  83. ^ "COVID: Germany records first death from omicron variant". DW. 23 December 2021. from the original on 24 December 2021. Retrieved 23 December 2021.
  84. ^ "Australia: Omicron death, false negative COVID results". Al Jazeera. 27 December 2021. from the original on 27 December 2021. Retrieved 27 December 2021.
  85. ^ "U.S. CDC estimates Omicron variant to be 58.6% of cases, revises projection". Reuters. 28 December 2021. Retrieved 15 April 2022.
  86. ^ "S.Korea reports first deaths linked to Omicron coronavirus variant – Yonhap". Reuters. 3 January 2022. from the original on 3 January 2022. Retrieved 3 January 2022.
  87. ^ a b "Statement on the update of WHO's working definitions and tracking system for SARS-CoV-2 variants of concern and variants of interest" (Statement). World Health Organization. 16 March 2023. Retrieved 20 May 2023.
  88. ^ Goodman, Brenda (29 March 2022). "Omicron subvariant BA.2 is now the dominant strain of Covid-19 in the US, CDC says". CNN. Retrieved 29 March 2022.
  89. ^ McDade, Aaron (29 March 2022). "Omicron BA.2 sub-variant now dominant in U.S., CDC says". Newsweek. Retrieved 29 March 2022.
  90. ^ CDC (28 March 2020). "COVID Data Tracker". Centers for Disease Control and Prevention. Retrieved 29 March 2022.
  91. ^ Gretchen Vogel (22 May 2022). "New versions of Omicron are masters of immune evasion". Science.
  92. ^ "BioNTech says it could tweak Covid vaccine in 100 days if needed". The Guardian. 26 November 2021. from the original on 27 November 2021. Retrieved 27 November 2021.
  93. ^ "Novavax developing vaccine that targets new COVID-19 variant". CBS Baltimore Staff. 30 November 2021. from the original on 2 December 2021. Retrieved 4 December 2021.
  94. ^ Maddipatla M, Roy M (26 November 2021). "Maryland-Based Vaccine Manufacturer Developing COVID-19 Vaccine That Targets Omicron Variant". Reuters. from the original on 28 November 2021. Retrieved 30 November 2021.
  95. ^ "Sputnik V maker: Vaccine could be adapted to fight omicron". ABC News. Moscow. Associated Press. 29 November 2021. from the original on 2 December 2021. Retrieved 29 November 2021.
  96. ^ "Sinovac and world's Covid-19 vaccine makers 'ready' to produce Omicron jab". South China Morning Post. 29 November 2021. from the original on 30 November 2021. Retrieved 29 November 2021.
  97. ^ "Sinovac prevê atualização da Coronavac para variante Ômicron em até três meses" [Sinovac plans to update Coronavac to the Omicron variant within three months]. CNN Brazil (in Portuguese). 7 December 2021. from the original on 9 December 2021. Retrieved 9 December 2021.
  98. ^ "Cuba to update domestic vaccine to battle Omicron". Al Jazeera. 2 December 2021. from the original on 20 December 2021. Retrieved 20 December 2021.
  99. ^ Spencer K (10 January 2022). "Pfizer CEO says omicron vaccine will be ready in March". CNBC. from the original on 26 January 2022. Retrieved 27 January 2022.
  100. ^ "Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern". WHO. 26 November 2021. from the original on 26 November 2021.
  101. ^ "WHO cautions against imposing travel restrictions due to new variant". Reuters. Geneva. 26 November 2021. from the original on 26 November 2021. Retrieved 26 November 2021.
  102. ^ "Implications of the emergence and spread of the SARS-CoV-2 B.1.1.529 variant of concern (Omicron) for the EU/EEA" (PDF). ecdc.europa.eu. (PDF) from the original on 26 November 2021. Retrieved 26 November 2021.
  103. ^ a b "Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern". World Health Organization. 26 November 2021. from the original on 26 November 2021. Retrieved 26 November 2021.
  104. ^ Nebehay S, Winning A (26 November 2021). "WHO names new COVID variant omicron, cautions against travel measures". Reuters. from the original on 26 November 2021. Retrieved 26 November 2021.
  105. ^ a b "Omicron poses very high global risk, world must prepare -WHO". Reuters. Geneva. 29 November 2021. from the original on 30 November 2021. Retrieved 30 November 2021.
  106. ^ "Covid live updates today: Omicron variant, symptoms, vaccines efficacy, restrictions..." en.as. 28 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021.
  107. ^ "World closing its doors to African countries due to omicron". aa.com. 30 November 2021. from the original on 30 November 2021. Retrieved 30 November 2021.
  108. ^ Yong C (26 November 2021). "Singapore bans travellers from 7 African countries; no cases of new Covid-19 variant here". The Straits Times. Singapore. from the original on 26 November 2021. Retrieved 26 November 2021.
  109. ^ [Anvisa recommends flight restrictions in view of the new covid-19 variant]. agenciabrasil.ebc.com.br. 26 November 2021. Archived from the original on 26 November 2021. Retrieved 27 November 2021.
  110. ^ Kennedy M, Price RD (26 November 2021). "'It's Coming': NY Declares State of Emergency Ahead of Potential Omicron Spike". NBC New York. from the original on 26 November 2021. Retrieved 27 November 2021.
  111. ^ "Switzerland announces new restrictions for Israelis after the discovery of Omicron". Globally 24. from the original on 27 November 2021. Retrieved 27 November 2021.
  112. ^ Winning A, Cocks T (26 November 2021). "South Africa says travel bans over new variant unjustified". Reuters. from the original on 26 November 2021. Retrieved 26 November 2021.
  113. ^ Zwi A (28 November 2021). "Travel bans aren't the answer to stopping new COVID variant Omicron". The Conversation. from the original on 28 November 2021. Retrieved 28 November 2021.
  114. ^ "EXCLUSIVE South Africa delays COVID vaccine deliveries as inoculations slow". Reuters. 24 November 2021. from the original on 28 November 2021. Retrieved 28 November 2021.
  115. ^ Kaitlan Collins and Kate Sullivan (29 November 2021). "Biden says new Omicron variant is 'cause for concern, not a cause for panic'". CNN. from the original on 2 December 2021. Retrieved 1 December 2021.
  116. ^ "New COVID-19 restrictions in effect for parts of Canada; some productions cancelled". CTVNews. 20 December 2021. from the original on 20 December 2021. Retrieved 20 December 2021.
  117. ^ "B.C. enacts social gathering and event capacity limits as Omicron variant spreads". Global News. from the original on 19 December 2021. Retrieved 18 December 2021.
  118. ^ "B.C. limits indoor gatherings, cancels New Year's Eve events as Omicron picks up speed". CBC News. 17 December 2021. from the original on 20 December 2021. Retrieved 17 December 2021.
  119. ^ "Quebec shutting down schools, bars, gyms tonight as COVID-19 cases soar". CTV News Montreal. 20 December 2021. from the original on 20 December 2021. Retrieved 20 December 2021.
  120. ^ Meijer BH, van den Berg S (18 December 2021). "Netherlands to go into strict Christmas lockdown". Reuters. from the original on 2 January 2022. Retrieved 2 January 2022.
  121. ^ "As Omicron threatens a global surge, some countries shorten COVID-19 booster timelines". Reuters. 20 December 2022. from the original on 15 January 2022. Retrieved 15 January 2022.
  122. ^ Gregg A (26 November 2021). "Dow plunges more than 900 points as new coronavirus variant sends global markets reeling". Washington Post. from the original on 26 November 2021. Retrieved 26 November 2021.
  123. ^ "'Omicron' cryptocurrency soars on new variant". www.msn.com. from the original on 1 December 2021. Retrieved 1 December 2021.
  124. ^ Davies P (26 November 2021). "Bitcoin's price has slumped after a new COVID variant was found. Why?". euronews. from the original on 27 November 2021. Retrieved 27 November 2021.
  125. ^ "South African markets sink on new Covid-19 variant". Moneyweb. 26 November 2021. from the original on 27 November 2021. Retrieved 29 November 2021.
  126. ^ "Rand tanks as UK red lists South Africa again amid new Covid variant". from the original on 26 November 2021. Retrieved 29 November 2021.
  127. ^ . enca.com. Archived from the original on 26 November 2021. Retrieved 29 November 2021.
  128. ^ "Omicron raises uncertainty around inflation, says Powell". BBC News. 2 December 2021. from the original on 1 December 2021. Retrieved 1 December 2021.
  129. ^ "Selection analysis identifies significant mutational changes in Omicron that are likely to influence both antibody neutralization and Spike function (Part 1 of 2)". 5 December 2021.
  130. ^ Cella, Eleonora; Benedetti, Francesca; Fabris, Silvia; Borsetti, Alessandra; Pezzuto, Aldo; Ciotti, Marco; Pascarella, Stefano; Ceccarelli, Giancarlo; Zella, Davide; Ciccozzi, Massimo; Giovanetti, Marta (2021). "SARS-CoV-2 Lineages and Sub-Lineages Circulating Worldwide: A Dynamic Overview". Chemotherapy. 66 (1–2): 3–7. doi:10.1159/000515340. PMC 8089399. PMID 33735881.
  131. ^ Khandia R, Singhal S, Alqahtani T, Kamal MA, El-Shall NA, Nainu F, et al. (June 2022). "Emergence of SARS-CoV-2 Omicron (B.1.1.529) variant, salient features, high global health concerns and strategies to counter it amid ongoing COVID-19 pandemic". Environmental Research. 209: 112816. Bibcode:2022ER....209k2816K. doi:10.1016/j.envres.2022.112816. PMC 8798788. PMID 35093310.
  132. ^ Hong Q, Han W, Li J, Xu S, Wang Y, Xu C, et al. (April 2022). "Molecular basis of receptor binding and antibody neutralization of Omicron". Nature. 604 (7906): 546–552. Bibcode:2022Natur.604..546H. doi:10.1038/s41586-022-04581-9. PMID 35228716. S2CID 247167987.
  133. ^ Mileto D, Micheli V, Fenizia C, Cutrera M, Gagliardi G, Mancon A, et al. (December 2022). "Reduced neutralization of SARS-CoV-2 Omicron variant by BNT162b2 vaccinees' sera: a preliminary evaluation". Emerging Microbes & Infections. 11 (1): 790–792. doi:10.1080/22221751.2022.2045878. PMC 8920392. PMID 35196967.
  134. ^ Zhang L, Mann M, Syed ZA, Reynolds HM, Tian E, Samara NL, et al. (November 2021). "Furin cleavage of the SARS-CoV-2 spike is modulated by O-glycosylation". Proceedings of the National Academy of Sciences of the United States of America. 118 (47): e2109905118. Bibcode:2021PNAS..11809905Z. doi:10.1073/pnas.2109905118. PMC 8617502. PMID 34732583. S2CID 242937417.
  135. ^ Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D (April 2020). "Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein". Cell. 181 (2): 281–292.e6. doi:10.1016/j.cell.2020.02.058. PMC 7102599. PMID 32155444.
sars, omicron, variant, omicron, variant, sars, first, reported, world, health, organization, network, genomics, surveillance, south, africa, november, 2021, first, detected, botswana, spread, become, predominant, variant, circulation, around, world, following. Omicron B 1 1 529 is a variant of SARS CoV 2 first reported to the World Health Organization WHO by the Network for Genomics Surveillance in South Africa on 24 November 2021 10 11 It was first detected in Botswana and has spread to become the predominant variant in circulation around the world 12 Following the original B 1 1 529 variant several subvariants of Omicron have emerged including BA 1 BA 2 BA 3 BA 4 and BA 5 13 Since October 2022 two subvariants of BA 5 called BQ 1 and BQ 1 1 have emerged SARS CoV 2 VariantOmicronScientifically accurate atomic model of the external structure of SARS CoV 2 Each ball is an atom General detailsWHO DesignationOmicronLineageB 1 1 529First detectedSouth AfricaDate reported24 November 2021 2 years ago 2021 11 24 StatusVariant of concernSymptomsAsymptomatic infection 1 body ache 1 cough 1 fainting 2 fatigue 3 fever headache 4 loss of smell or taste 5 6 less common nasal congestion or running nose 4 night sweats 7 unique Omicron symptom upper respiratory tract infection 8 skin rash 9 sneezing 4 sore throat 2 Major variantsAlpha B 1 1 7 Beta B 1 351 Gamma P 1 Delta B 1 617 2 Omicron B 1 1 529 BA 1 B 1 1 529 1 BA 2 B 1 1 529 2 BA 3 B 1 1 529 3 BA 4 B 1 1 529 4 BA 5 B 1 1 529 5 vteThree doses of a COVID 19 vaccine provide protection against severe disease and hospitalisation caused by Omicron and its subvariants 14 15 16 17 For three dose vaccinated individuals the BA 4 and BA 5 variants are more infectious than previous subvariants but there is no evidence of greater sickness or severity 13 18 19 Contents 1 Classification 2 History 2 1 Origin hypotheses 2 2 Spread 3 Reactions 3 1 Vaccine producers 3 2 World Health Organization 3 3 International response 3 4 Market reactions 4 Biology 4 1 Mutations 5 Subvariants 5 1 BA 2 5 1 1 Spread 5 1 2 XE 5 1 3 BA 2 12 5 1 4 BA 2 75 and BA 2 75 2 5 1 4 1 XBB and XBB 1 5 1 4 2 EG 5 and EG 5 1 5 1 5 HV 1 5 1 6 BA 2 86 5 2 BA 3 5 3 BA 4 and BA 5 5 3 1 BQ 1 and BQ 1 1 6 Transmission 6 1 In humans 6 2 In non human animals 6 3 Surfaces 7 Vaccine effectiveness 7 1 BA 1 and BA 2 7 2 BA 4 and BA 5 7 2 1 BQ 1 and BQ 1 1 8 Vaccine adjustments 9 Signs and symptoms 10 Virulence 11 Diagnosis 11 1 PCR testing 11 1 1 BA 1 and BA 2 differences 12 Treatment 13 Epidemiology 13 1 Reported cases 14 See also 15 Notes 16 References 17 External linksClassification edit nbsp Omicron variant and other major or previous variants of concern of SARS CoV 2 depicted in a tree scaled radially by genetic distance derived from Nextstrain on 1 December 2021On 26 November 2021 the WHO s Technical Advisory Group on SARS CoV 2 Virus Evolution declared PANGO lineage B 1 1 529 a variant of concern and designated it with the Greek letter omicron 10 The WHO skipped the preceding letters nu and xi in the Greek alphabet to avoid confusion with the similarities of the English word new and the Chinese surname Xi 20 The name of the variant has occasionally been mistaken as Omnicron among some English speakers due to a lack of familiarity with the Greek alphabet and the relative frequency of the Latin prefix omni in other common speech 21 22 The GISAID project has assigned it the clade identifier GR 484A 23 and the Nextstrain project has assigned it the clade identifiers 21K and 21L both belonging to a larger Omicron group 21M 24 History editOmicron was first detected on 22 November 2021 in laboratories in Botswana and South Africa based on samples collected on 11 16 November 25 with the first known samples collected in Johannesburg South Africa on 8 November 2021 26 The first known cases outside of South Africa were two people who travelled on 11 November one who flew from South Africa to Hong Kong via Qatar and another who travelled from Egypt to Belgium via Turkey 27 28 On 26 November 2021 WHO designated B 1 1 529 as a variant of concern and named it Omicron after the fifteenth letter in the Greek alphabet 10 As of 6 January 2022 the variant had been confirmed in 149 countries 29 Origin hypotheses edit Omicron did not evolve from any other variant but instead diverged on a distinct track perhaps in mid 2020 29 30 Competing hypotheses are being examined One origin hypothesis is that various mutations in the Omicron variant comprising a 9 nucleotide sequence may have been acquired from another coronavirus known as HCoV 229E responsible for the common cold 31 This is not entirely unexpected at times viruses within the body acquire and swap segments of genetic material from each other and this is one common means of mutation 31 A link with HIV infection may explain a large number of mutations in the sequence of the Omicron variant 32 Indeed in order to be affected by such a high number of mutations the virus must have been able to evolve a long time without killing its host which can occur in people with a weakened immune system who receive enough medical care to survive 32 33 This is the case in HIV patients in South Africa who represent about 14 of the population as of 2017 34 HIV prevention could be key to reducing the risk of uncontrolled HIV driving the emergence of SARS CoV 2 variants 32 One hypothesis to explain the novel mutations is that SARS CoV 2 was transmitted from humans to mice and mutated in a population of mice sometime between mid 2020 and late 2021 before reinfecting humans 30 On 1 December 2022 a team of researchers from the Charite Berlin published a now retracted study in Science journal that claimed that data revealed genetically diverse Omicron ancestors already existed across Africa by August 2021 35 After a re analysis because of doubts 36 the team retracted the article on 20 December 2022 due to contamination of the samples 37 38 Spread edit On 24 November 2021 the variant was first reported to the WHO from South Africa based on samples that had been collected from 14 to 16 November 25 South African scientists were first alerted by samples from the very beginning of November where the PCR tests had S gene target failure occurs in a few variants but not in Delta which dominated in the country in October and by a sudden increase of COVID 19 cases in Gauteng sequencing revealed that more than 70 percent of samples collected in the province between 14 and 23 November were a new variant 39 The first confirmed specimens of Omicron were collected on 8 November 2021 in South Africa and on 9 November in Botswana 40 Likely Omicron SGTF samples had occurred on 4 November 2021 in Pretoria South Africa citation needed When WHO was alerted on 24 November Hong Kong was the only place outside Africa that had confirmed a case of Omicron one person who traveled from South Africa on 11 November and another traveler who was cross infected by this case while staying in the same quarantine hotel 27 On 25 November one confirmed case was identified in Israel from a traveler returning from Malawi 41 along with two who returned from South Africa and one from Madagascar 42 All four initial cases reported from Botswana occurred among fully vaccinated individuals 43 On 26 November Belgium confirmed its first case an unvaccinated person who had travelled from Egypt via Turkey on 11 November 28 All three initial confirmed and suspected cases reported from Israel occurred among fully vaccinated individuals 41 as did a single suspected case in Germany 44 On 27 November two cases were detected in the United Kingdom another two in Munich Germany and one in Milan Italy 45 On 28 November 13 cases were confirmed in the Netherlands among the 624 airline passengers who arrived from South Africa on 26 November 46 Confirmation of a further 5 cases among these passengers followed later 47 Entry into the Netherlands generally required having been vaccinated or PCR tested or having recovered The passengers of these two flights had been tested upon arrival because of the newly imposed restrictions which were set in place during their flight after which 61 tested positive for SARS CoV 2 48 A further two cases were detected in Australia Both people landed in Sydney the previous day and travelled from southern Africa to Sydney Airport via Doha Airport The two people who were fully vaccinated entered isolation 12 other travellers from southern Africa also entered quarantine for fourteen days while about 260 other passengers and crew on the flight were directed to isolate 49 Two travellers from South Africa who landed in Denmark tested positive for COVID 19 it was confirmed on 28 November that both carried the Omicron variant 50 51 On the same day Austria also confirmed its first Omicron case 52 A detected Omicron case was reported in the Czech Republic from a traveler who spent time in Namibia 53 Canada also reported its first Omicron cases with two from travelers from Nigeria therefore becoming the first North American country to report an Omicron case 54 On 29 November a positive case was recorded in Darwin Australia The person arrived in Darwin on a repatriation flight from Johannesburg South Africa on 25 November and was taken to a quarantine facility where the positive test was recorded 55 Two more people who travelled to Sydney from southern Africa via Singapore tested positive 56 Portugal reported 13 Omicron cases all of them members of a soccer club 57 Sweden also confirmed their first case on 29 November 58 as did Spain when a traveler came from South Africa 59 On 30 November the Netherlands reported that Omicron cases had been detected in two samples dating back as early as 19 November 60 A positive case was recorded in Sydney from a traveller who had visited southern Africa before travel restrictions were imposed and was subsequently active in the community 61 Japan also confirmed its first case 62 Two Israeli doctors tested positive and entered isolation Both of them had received three shots of the Pfizer vaccine prior to testing positive 63 In Brazil three cases of the Omicron variant were confirmed in Sao Paulo 64 Another five are under suspicion 65 66 A person in Leipzig Germany with no travel history nor contact with travellers tested positive for Omicron 67 On 1 December the Omicron variant was detected in three samples in Nigeria that had been collected from travelers from South Africa within the last week 68 69 On the same day public health authorities in the United States announced the country s first confirmed Omicron case A resident of San Francisco who had been vaccinated returned from South Africa on 22 November began showing mild symptoms on 25 November 70 and was confirmed to have a mild case of COVID 19 on 29 November 71 Ireland and South Korea also reported their first cases 72 South Korea reported its cases from five travelers arriving in South Korea from Nigeria 73 On 2 December Dutch health authorities confirmed that all 14 passengers with confirmed Omicron infection on 26 November had been previously vaccinated 74 The same day the Norwegian Institute of Public Health confirmed that 50 attendees of a company Christmas party held at a restaurant in Norway s capital Oslo were infected with the Omicron variant 75 France has confirmed only 25 cases of the new Omicron variant but officials say the number could jump significantly in the coming weeks 76 By 6 December Malaysia confirmed its first case of the variant The case was a South African student entering to study at a private university 77 In Namibia 18 cases out of 19 positive COVID 19 samples that had been collected between 11 and 26 November were found to be Omicron indicating a high level of prevalence in the country 78 Fiji also confirmed two positive cases of the variant They travelled from Nigeria arriving in Fiji on November 25 79 On 9 December Richard Mihigo coordinator of the World Health Organisation s Immunisation and Vaccine Development Programme for Africa announced that Africa accounted for 46 of reported cases of the Omicron variant globally 80 On 13 December the first death of a person with Omicron was reported in the UK 81 On 16 December New Zealand confirmed its first case of the Omicron variant an individual who had traveled from Germany via Dubai 82 The first death of a person with Omicron was reported in Germany on 23 December 83 and in Australia on 27 December 84 By Christmas 2021 the Omicron Strain became dominant in the US 85 On 3 January 2022 South Korea reported the first two deaths of people who tested positive post mortem for Omicron 86 In February 2022 Omicron accounted for 98 of publicly available genetic sequences worldwide 87 On 29 March 2022 Omicron subvariant BA 2 overtook BA 1 and became the dominant strain in the U S 88 89 90 As of May 2022 BA 2 12 1 was spreading in the US and two new subvariants of Omicron named BA 4 and BA 5 first detected in January 2022 spread in South Africa All 3 subvariants have spike protein mutations of L452 and elude immunity from prior BA1 infection 91 On 16 March 2023 without seeing a reduction in the threat to public health the WHO stopped classifying Omicron as a variant of concern in order to maintain this classification only for new threats Instead the WHO classified its subvariants as variants of interest and under monitoring 87 Reactions editVaccine producers edit On 26 November 2021 BioNTech said it would know in two weeks whether the current vaccine is effective against the variant and that an updated vaccine could be shipped in 100 days if necessary AstraZeneca Moderna and Johnson amp Johnson were also studying the variant s impact on the effectiveness of their vaccines 92 On the same day Novavax stated that it was developing an updated vaccine requiring two doses for the Omicron variant which the company expected to be ready for testing and manufacturing within a few weeks 93 94 On 29 November 2021 The Gamaleya Institute said that Sputnik Light should be effective against the variant that it would begin adapting Sputnik V and that a modified version could be ready for mass production in 45 days 95 Sinovac said it could quickly mass produce an inactivated vaccine against the variant and that it was monitoring studies and collecting samples of the variant to determine if a new vaccine is needed 96 On 7 December 2021 at a symposium in Brazil with its partner Instituto Butantan Sinovac said it would update its vaccine to the new variant and make it available in three months 97 On 2 December the Finlay Institute was already developing a version of Soberana Plus against the variant 98 Pfizer hoped to have a vaccine targeted to immunize against Omicron ready by March 2022 99 World Health Organization edit On 26 November 2021 the WHO asked nations to enhance surveillance and sequencing efforts submit complete genome sequences and associated metadata to a publicly available database such as GISAID report initial cases clusters associated with virus of concern infection to WHO through the IHR mechanism where capacity exists and in coordination with the international community perform field investigations and laboratory assessments to improve understanding of the potential impacts of the virus of concern on COVID 19 epidemiology severity and the effectiveness of public health and social measures diagnostic methods immune responses antibody neutralization or other relevant characteristics 100 On 26 November 2021 WHO advised countries not to impose new restrictions on travel instead recommending a risk based and scientific approach to travel measures 101 On the same day the European Centre for Disease Prevention and Control ECDC reported modeling indicating that strict travel restrictions would delay the variant s impact on European countries by two weeks possibly allowing countries to prepare for it 102 As with other variants the WHO recommended that people continue to keep enclosed spaces well ventilated avoid crowding and close contact wear well fitting masks clean hands frequently and get vaccinated 103 104 On 29 November 2021 the WHO said cases and infections were expected among those vaccinated albeit in a small and predictable proportion 105 International response edit After the WHO announcement on the same day several countries announced travel bans from southern Africa in response to the identification of the variant including the United States which banned travel from eight African countries 106 although as of 30 November 2021 it notably did not ban travel from any European countries Israel Canada or Australia where cases were also detected at the time the bans were announced Other countries that also implemented travel bans include Japan Canada the European Union Israel Australia the United Kingdom Singapore Malaysia Indonesia Morocco and New Zealand 107 108 On 26 November 2021 the Brazilian Health Regulatory Agency recommended flight restrictions regarding the new variant 109 The state of New York declared a state of emergency ahead of a potential Omicron spike although no cases had yet been detected in the state or the rest of the United States 110 On 27 November 2021 Switzerland introduced obligatory tests and quarantine for all visitors arriving from countries where the variant was detected which originally included Belgium and Israel 111 On 26 November 2021 South African Minister of Health Joe Phaahla defended his country s handling of the pandemic and said that travel bans went against the norms and standards of the World Health Organization 112 Some speculated that travel bans could have a significant impact on South Africa s economy by limiting tourism and could lead to other countries with economies that are reliant on tourism to hide the discovery of new variants of concern Low vaccine coverage in less developed nations could create opportunities for the emergence of new variants and these nations also were struggling to gain intellectual property to develop and produce vaccines locally 113 At the same time inoculation had slowed in South Africa due to vaccine hesitancy and apathy with a nationwide vaccination rate of only 35 as of November 24 2021 114 On 29 November 2021 the WHO warned countries that the variant poses a very high global risk with severe consequences and that they should prepare by accelerating vaccination of high priority groups and strengthening health systems WHO director general Tedros Adhanom described the global situation as dangerous and precarious and called for a new agreement on the handling of pandemics as the current system disincentivizes countries from alerting others to threats that will inevitably land on their shores CEPI CEO Richard Hatchett said that the variant fulfilled predictions that transmission of the virus in low vaccination areas would accelerate its evolution 105 In preparation for the Omicron variant arriving in the United States President Joe Biden stated that the variant is cause for concern not panic reiterated that the government was prepared for the variant and would have it under control and that large scale lockdowns similar to the ones in 2020 near the beginning of the pandemic were off the table for now 115 In mid December 2021 multiple Canadian provinces reinstated restrictions on gatherings and events such as sports tournaments and tightened enforcement of proof of vaccination orders British Columbia expressly prohibited any non seated organized New Year s Eve event 116 117 118 while Quebec announced a partial lockdown on 20 December 2021 ordering the closure of all bars casinos gyms schools and theatres as well as imposing restrictions on the capacity and operating hours of restaurants and the prohibition of spectators at professional sporting events 119 On 18 December 2021 the Netherlands government announced a lockdown intended to prevent spread of the variant during the holiday period 120 In late December 2021 some countries shortened the typical six month interval for a booster dose of the vaccine to prepare for a wave of Omicron as two doses are not enough to stop the infection UK South Korea and Thailand reduced to three months Belgium four months France Singapore Taiwan Italy and Australia five months Finland reduced it to three months for risk groups Other countries continued with a six month booster schedule While antibody levels begin to drop at four months a longer interval usually allows time for the immune system s response to mature 121 Market reactions edit Main article Financial market impact of the COVID 19 pandemic On 26 November 2021 worry about the potential economic impact of the Omicron variant led to a drop in global markets including the worst drop of the Dow Jones Industrial Average in 2021 led by travel related stocks The price of Brent Crude and West Texas Intermediate oil fell 10 and 11 7 respectively 122 Cryptocurrency markets were also routed 123 124 and the South African rand also hit an all time low for 2021 trading at over 16 rand to the dollar losing 6 of its value in November 125 126 127 In early December 2021 Jerome Powell the chairman of the Federal Reserve testified before the U S Senate Committee on Banking that The recent rise in COVID 19 cases and the emergence of the Omicron variant pose downside risks to employment and economic activity and increased uncertainty for inflation 128 Biology edit nbsp The genomic sequence of the Omicron variant is pictured aboveMutations edit As of June 2022 Omicron had about 50 mutations relative to the Wuhan Hu 1 or B variant 129 130 which is more than any previous SARS CoV 2 variant Thirty two of these pertained to the spike protein which most vaccines target to neutralise the virus 131 As of December 2021 many mutations were novel and not found in previous variants 40 As of April 2022 the variant was characterised by 30 amino acid changes three small deletions and one small insertion in the spike protein compared with the original virus of which 15 are located in the receptor binding domain residues 319 541 132 As of December 2022 the virus carried a number of changes and deletions in other genomic regions For example three mutations at the furin cleavage site which facilitates its transmission 133 134 nbsp nbsp Illustration of the locations of the Omicron mutations in the spike protein top view left and side view right showing amino acid substitutions yellow deletions red and insertions green In this trimeric structure two monomers gray and light blue have their receptor binding domains in the down conformation while one dark blue is in the up or open conformation Mutation data from WHO 103 structure from PDB 6VYB 135 nbsp Comparison of mutation prevalence for ORF1a ORF1b and S genes of Omicron lineages that are designated Variants of Concern Characteristic mutations for a lineage are defined as nonsynonymous substitutions or deletions that occur in gt 75 of sequences within that lineage 136 Subvariants editSeveral subvariants of Omicron have been discovered and new ones continue to emerge 12 There are 310 Pango lineages clarification needed currently associated with the Omicron variant 137 The standard sublineage is now referred to as BA 1 or B 1 1 529 1 and the two other sublineages are known as BA 2 or B 1 1 529 2 and BA 3 or B 1 1 529 3 138 In mid 2022 BA 4 or B 1 1 529 4 and BA 5 or B 1 1 529 5 were detected in several countries 139 They share many mutations but also significantly differ In general BA 1 and BA 2 share 32 mutations but differ by 28 140 BA 1 has itself been divided in two the original BA 1 and BA 1 1 or B 1 1 529 1 1 where the main difference is that the latter has a R346K mutation 141 Standard PCR and rapid tests continue to detect all Omicron subvariants as COVID 19 but further tests are necessary to distinguish the subvariants from each other and from other COVID 19 variants 142 Defining mutations in theSARS CoV 2 Omicron variant Gene Amino acidORF1ab nsp3 K38Rnsp3 V1069Insp3 D1265nsp3 L1266Insp3 A1892Tnsp4 T492Insp5 P132Hnsp6 D105 107nsp6 A189Vnsp12 P323Lnsp14 I42VSpike A67VD69 70T95IG142D D143 145D211L212Iins214EPEG339DS371LS373PS375FK417NN440KG446SS477NT478KE484AQ493RG496SQ498RN501YY505HT547KD614GH655YN679KP681HN764KD796YN856KQ954HN969KL981FE T9IM D3GQ19EA63TN P13LD31 33R203KG204RSources UK Health Security Agency 143 CoVariants 24 BA 2 edit BA 2 was first detected in a sample from 15 November 2021 144 A preprint released in February 2022 published in May suggested that BA 2 was more transmissible than BA 1 and may cause more severe disease 145 This was later disproven by a study in late October 2022 that found BA 2 actually caused less severe disease relative to BA 1 which in turn caused less severe disease compared to the delta variant 146 Therapeutic monoclonal antibodies used to treat people infected with COVID 19 did not have much effect on BA 2 which was almost completely resistant to casirivimab and imdevimab and 35 times more resistant to sotrovimab than the BA 1 subvariant citation needed Spread edit As of 17 January 2022 BA 2 had been detected in at least 40 countries and in all continents except Antarctica 147 By 31 January it had been detected in at least 57 countries 148 In global samples collected from 4 February to 5 March and uploaded to GISAID BA 2 accounted for c 34 compared to 41 for BA 1 1 25 for BA 1 and less than 1 for BA 3 149 In a review two weeks later covering 16 February to 17 March BA 2 had become the most frequent 150 151 Based on GISAID uploads BA 1 peaked in early January 2022 after which it was overtaken by both BA 1 1 and BA 2 152 In North America parts of Europe and parts of Asia BA 1 was first outcompeted by BA 1 1 For example in the United States France and Japan BA 1 1 became the dominant subvariant in January 2022 153 154 155 By late December 2021 early January 2022 BA 2 had become dominant in parts of India already making up almost 80 percent in Kolkata in late December 2021 156 and the Philippines had become frequent in Scandinavia South Africa and Singapore and was showing signs of growth in Germany and the United Kingdom 157 158 159 160 In Japan which has quarantine and detailed screening of all international travellers as of 24 January the vast majority of BA 2 had been detected in people that had arrived from India or the Philippines with cases going back at least to 1 December 2021 far fewer BA 1 or other variants were detected among arrivals from the two countries in that period but small numbers had also been detected in people arriving from other countries 161 162 163 In Denmark the first BA 2 was in a sample collected on 5 December 2021 164 By week fifty 13 19 December it had started to increase with BA 2 being at around 2 percent of sequenced cases compared to 46 percent BA 1 remaining Delta The frequency of both Omicron subvariants continued to increase throughout the last half of December and by the end of the year BA 2 had reached 20 percent and BA 1 peaked at 72 percent In January 2022 BA 1 began decreasing whereas BA 2 continued its increase By the second week of 2022 the frequency of the two was almost equal both being near 50 percent 164 In the following week BA 2 became clearly dominant in Denmark with 65 percent of new cases 165 Trends from the other Scandinavian countries India South Africa and the United Kingdom also showed that BA 2 was increasing in proportion to BA 1 166 167 In early February 2022 it had become the dominant subvariant in South Africa in late February it had become dominant in Germany and in early March it had become dominant in the United Kingdom 168 169 170 In early March BA 1 1 was still heavily dominant in the United States having overtaken BA 1 in January but BA 2 was increasing in frequency later becoming dominant in the US by 29 March 153 171 XE edit A new BA 1 BA 2 recombinant was isolated in the UK in January 2022 dubbed the XE recombinant It was found by the WHO to be potentially 10 more transmissible than BA 2 making it about 43 to 76 to more transmissible than BA 1 and making the XE recombinant the most contagious variant identified at the time 172 BA 2 12 edit There were two new BA 2 subvariants detected in the US state of New York which are BA 2 12 or B 1 1 529 2 12 and BA 2 12 1 or B 1 1 529 2 12 1 both of which have a significant growth advantage of 23 27 over BA 2 and contributing to a rise in infections in central New York centred on Syracuse and Lake Ontario which later became dominant by May 24 2022 in the US 173 BA 2 75 and BA 2 75 2 edit The subvariant BA 2 75 or B 1 1 529 2 75 nicknamed Centaurus by the media 174 first detected in India in May 2022 was classified as variant under monitoring by the WHO 175 Additional newer mutations in this line like BA 2 75 2 aka B 1 1 529 2 75 2 or Chiron may be capable of escaping neutralizing antibodies 176 XBB and XBB 1 edit XBB a recombinant of the BA 2 10 1 1 and BA 2 75 3 1 1 1 sublineages 177 is an Omicron subvariant first detected in August 2022 178 On 20 October 2022 the chief scientist of the World Health Organization WHO Soumya Swaminathan warned that the XBB subvariant of Omicron may cause infections in some countries while the severity of the new variants is not yet known 179 On 9 January 2023 the European CDC said there was suggestive evidence the XBB 1 5 variant had a growth advantage after becoming dominant in the US it might become dominant in Europe in the following months 180 From preliminary evidence they had assessed the XBB variants had no effect on disease severity and transmissibility 181 In early March 2023 XBB 1 16 first appeared in India and caused a surge of hospitalizations 182 It was nicknamed Arcturus by T Ryan Gregory 182 183 184 EG 5 and EG 5 1 edit EG 5 or XBB 1 9 2 5 nicknamed by some media Eris 185 is a descendant of XBB 1 9 2 The lineage was detected as early as February 2023 186 On 6 August the UK Health Security Agency reported the EG 5 strain was responsible for one in seven new cases in the UK during the third week of July 187 It was identified as a variant of interest by the WHO on 9 August 2023 Its key difference from other strains is a F456L amino acid mutation 188 HV 1 edit HV 1 or XBB 1 9 2 5 1 6 1 is a sublineage of XBB 1 9 2 of the Omicron family first detected in July 2023 HV 1 overtook EG 5 as the dominant subvariant in the U S in October 2023 189 In October experts stated that there was no evidence that HV 1 was more severe or transmissible than other Omicron subvariants 190 BA 2 86 edit Main article BA 2 86 In mid August 2023 the CDC and WHO announced they were monitoring another subvariant of Omicron BA 2 86 a descendant of the BA 2 subvariant The WHO has placed BA 2 86 as a VUM variant under monitoring as it is reported to have more than 30 mutations 191 As of 18 August cases had been reported from four countries three in Denmark and a single each in Israel the UK and the US On the same date UK healthcare authorities noted that its almost simultaneous appearance in several countries still operating detailed genomic surveillance indicated that it likely already was spreading more widely internationally 192 The first case of BA 2 86 was collected on 24 July 2023 according to the WHO BA 3 edit The third Omicron sublineage BA 3 is very rare It has the same S gene target failure SGTF deletion D69 70 as BA 1 citation needed BA 4 and BA 5 edit In April 2022 the WHO announced it was tracking the BA 4 and BA 5 subvariants with BA 4 having been detected in South Africa Botswana Denmark Scotland and England 193 Early indications from data collected in South Africa suggested BA 4 and BA 5 have a significant growth advantage over BA 2 which by 12 May earned the status Variant of Concern by the European Centre for Disease Prevention and Control and by 20 May by the UK Health Security Agency 194 195 196 197 BA 5 was dominant in Portugal by 25 May accounting for two thirds of all new cases there 198 By 24 June BA 4 and BA 5 together had become dominant variants in the UK and Germany 199 200 201 202 These two subvariants became dominant in the United States by 28 June 203 204 By late June BA 5 became the dominant subvariant in France with 59 of new cases linked to it 205 206 On 10 May 2022 a case of a new subvariant BA 5 2 1 was reported in California 207 On 10 July the city of Shanghai reported its first case of BA 5 2 1 in a man who had flown in from Uganda sparking a new wave of testing 208 On 22 July the province of Ontario Canada announced that subvariant BA 5 2 1 overtook BA 2 12 1 as the main variant in circulation in Ontario around 2 July 209 Regeneron is reporting that BA 5 2 1 is the main variant in Australia Belgium Brunei Greece and Iceland 210 The government of Canada also reported in late June and July of the travelers arriving by air who test positive for COVID 19 a substantial proportion were BA 5 2 1 211 BF 7 is a shortened version of the sub variants full name which is BA 5 2 1 7 This sub variant is part of Omicron s BA 5 variant which had the highest number of reported cases globally accounting for 76 2 of all cases 212 BQ 1 and BQ 1 1 edit In October 2022 two BA 5 subvariants were found BQ 1 or B 1 1 529 5 3 1 1 1 1 1 and BQ 1 1 or B 1 1 529 5 3 1 1 1 1 1 1 213 214 215 The variants were originally most prevalent in France 216 As of 17 November 93 of sequences in France were Omicron sub lineage BA 5 and among the BA 5 sub lineages BQ 1 1 continued to rise 32 vs 25 in the prior week 217 In November 2022 in the US it was reported the variants were accounting for 44 of new infections Early laboratory tests found that these subvariants were better at escaping first and booster vaccines than previous variants 218 Transmission edit nbsp False color transmission electron micrograph of an Omicron variant coronavirus shown in pink replicating within the cytoplasm of an infected Vero cellIn humans edit In January 2022 William Schaffner professor of infectious diseases at Vanderbilt University Medical Center compared the contagiousness of the Omicron variant to that of the measles 219 On 15 December 2021 Jenny Harries head of the UK Health Security Agency told a parliamentary committee that the doubling time of COVID 19 in most regions of the UK was now less than two days despite the country s high vaccination rate She said that the Omicron variant of COVID 19 is probably the most significant threat since the start of the pandemic and that the number of cases in the next few days would be quite staggering compared to the rate of growth that we ve seen in cases for previous variants 220 A 2021 study suggested that mutations that promote breakthrough infections or antibody resistance like those in Omicron could be a new mechanism for viral evolution success of SARS CoV 2 and that such may become a dominating mechanism of its evolution 221 A preprint supports such an explanation of Omicron s spread suggesting that it primarily can be ascribed to the immune evasiveness rather than an inherent increase in the basic transmissibility 222 223 Studies showed the variant to escape the majority of existing SARS CoV 2 neutralizing antibodies including those in sera from vaccinated and convalescent individuals 224 225 226 227 Nevertheless existing vaccines were expected to protect against severe illness hospitalizations and deaths due to Omicron 228 and on an individual level the Omicron variant is milder than earlier variants that evolved when the antibody vaccination share was lower than it was when Omicron emerged 229 In contrast to other investigated variants Omicron showed substantial population level evasion of immunity from prior infection as well as a higher ability to evade immunity induced by vaccines 230 Later research found that the spread of Omicron likely contributed to significant natural immunity to reinfection 231 In non human animals edit In February 2022 the first confirmed case infecting a wild animal was confirmed by researchers at Pennsylvania State University in white tailed deer in Staten Island N Y 232 Surfaces edit Although transmission via fomites is rare preliminary data indicate that the variant lasts for 194 hours on plastic surfaces and 21 hours on skin compared with just 56 and 7 hours respectively for the original strain 233 234 Vaccine effectiveness editPfizer BioNTech BNT162b2 and Moderna mRNA 1273 mRNA vaccines provide reduced protection against asymptomatic disease but do reduce the risk of serious illness 235 236 237 On 22 December 2021 the Imperial College COVID 19 Response Team reported an about 41 95 CI 37 45 lower risk of a hospitalization requiring a stay of at least 1 night compared to the Delta variant and that the data suggested that recipients of 2 doses of the Pfizer BioNTech the Moderna or the Oxford AstraZeneca vaccine were substantially protected from hospitalization 238 In January 2022 results from Israel suggested that a fourth dose is only partially effective against Omicron Many cases of infection broke through albeit a bit less than in the control group even though trial participants had higher antibody levels after the fourth dose 239 On 23 December 2021 Nature indicates that though Omicron likely weakens vaccine protection reasonable effectiveness against Omicron may be maintained with currently available vaccination and boosting approaches 240 241 In December studies some of which using large nationwide datasets from either Israel and Denmark found that vaccine effectiveness of multiple common two dosed COVID 19 vaccines is substantially lower against the Omicron variant than for other common variants including the Delta variant and that a new often a third dose a booster dose is needed and effective as it substantially reduces deaths from the disease compared to cohorts who received no booster but two doses 242 243 244 245 246 247 Vaccines continue to be recommended for Omicron and its subvariants Professor Paul Morgan immunologist at Cardiff University said I think a blunting rather than a complete loss of immunity is the most likely outcome The virus can t possibly lose every single epitope on its surface because if it did that spike protein couldn t work any more So while some of the antibodies and T cell clones made against earlier versions of the virus or against the vaccines may not be effective there will be others which will remain effective If half or two thirds or whatever it is of the immune response is not going to be effective and you re left with the residual half then the more boosted that is the better 248 Professor Francois Balloux of the Genetics Institute at University College London said From what we have learned so far we can be fairly confident that compared with other variants Omicron tends to be better able to reinfect people who have been previously infected and received some protection against COVID 19 That is pretty clear and was anticipated from the mutational changes we have pinpointed in its protein structure These make it more difficult for antibodies to neutralise the virus 249 BA 1 and BA 2 edit A January 2022 study by the UK Health Security Agency found that vaccines afforded similar levels of protection against symptomatic disease by BA 1 and BA 2 and in both it was considerably higher after two doses and a booster than two doses without booster 250 251 though because of the gradually waning effect of vaccines further booster vaccination may later be necessary 170 BA 4 and BA 5 edit In May 2022 a preprint indicated Omicron subvariants BA 4 and BA 5 could cause a large share of COVID 19 reinfections beyond the increase of reinfections caused by the Omicron lineage even for people who were infected by Omicron BA 1 due to increases in immune evasion especially for the unvaccinated However the observed escape of BA 4 and BA 5 from immunity by a BA 1 infection is more moderate than of BA 1 against studied prior cases of immunity such as immunity from specific vaccines 252 253 Immunity from an Omicron infection for unvaccinated and previously uninfected was found to be weak against non Omicron variants 254 albeit at the time Omicron is by a large margin the dominant variant in sequenced human cases 255 BQ 1 and BQ 1 1 edit Subvariants BQ 1 and BQ 1 1 were found in late 2022 to be better at escaping first and booster vaccines than previous variants and to have further reduced the effectiveness of monoclonal antibody treatments 256 Vaccine adjustments editSee also Universal coronavirus vaccine In June 2022 Pfizer and Moderna developed bivalent vaccines to protect against the SARS CoV 2 wild type and the Omicron variant The bivalent vaccines are well tolerated and offer immunity to Omicron superior to previous mRNA vaccines 257 In September 2022 the United States Food and Drug Administration FDA authorized the bivalent vaccines for use in the US 258 259 260 In June 2023 the FDA advised manufacturers that the 2023 2024 formulation of the COVID 19 vaccines for use in the US be updated to be a monovalent COVID 19 vaccine using the XBB 1 5 lineage of the Omicron variant 261 262 Signs and symptoms editMain article Symptoms of COVID 19 Loss of taste and smell seem to be uncommon compared to other strains 5 6 A unique reported symptom of the Omicron variant is night sweats 7 263 particularly with the BA 5 subvariant 264 265 A study performed between 1 and 7 December 2021 by the Center for Disease Control found that The most commonly reported symptoms were cough fatigue and congestion or runny nose making it difficult to distinguish from a less damaging variant or another virus 266 Research published in London on 25 December 2021 suggested the most frequent symptoms stated by users of the Zoe Covid app were a runny nose headaches fatigue sneezing and sore throats 4 A British Omicron case control observational study until March 2022 showed a reduction in odds of long COVID with the Omicron variant versus the Delta variant of 0 24 0 5 depending on age and time since vaccination 267 Virulence editAs of 6 January 2022 Omicron multiplied around 70 times faster than the Delta variant in the bronchi lung airways but evidence suggested it is less severe than previous variants especially compared to Delta 268 229 since it might be less able to penetrate deep lung tissue 269 As of January 2022 in southern California infections were 91 percent less fatal than the delta variant with 51 percent less risk of hospitalization 270 However the estimated difference in the intrinsic risk of hospitalization in England largely decreased to 0 30 percent when reinfections were excluded 271 As of 21 January 2022 the risk of hospitalization was the same in BA 1 and BA 2 based on reviews from Denmark India South Africa and the United Kingdom 272 149 165 273 Norwegian studies showed that the amount of virus in the upper airways was similar in those infected with BA 1 and BA 2 167 Diagnosis editSee also COVID 19 testingAs of November 2021 the chance of detecting an Omicron case particularly depended on a country s sequencing rate with South Africa sequencing far more samples than any other country in Africa but at a considerably lower rate than most Western nations 274 275 Sequencing the virus from a sample can take weeks limiting the early availability of data 276 In January 2022 the medicine and therapeutic regulatory agency Therapeutic Goods Administration TGA of the Australian Government had only tested one of their 23 approved COVID 19 rapid antigen tests RAT to verify it detected Omicron 277 The TGA later updated their approved list to show that all RATs which detected other variants could detect Omicron infections 278 In June 2022 the German federal Paul Ehrlich Institute published their findings that most RATs detected the Omicron Variant 279 PCR testing edit In December 2021 the US FDA published guidelines on how PCR tests would be affected by Omicron 280 Tests that detect multiple gene targets were to continue to identify the testee as positive for COVID 19 S gene dropout or target failure was proposed as a shorthand way of differentiating Omicron from Delta besides sequencing and genotyping 281 As of December 2021 Denmark and Norway have regarded cases found by their variant qPCR test which is relatively fast and checks several genes 282 as sufficient for counting it as Omicron before full sequencing 283 284 BA 1 and BA 2 differences edit As of 7 December 2021 it was known that BA 2 unlike BA 1 lacks the characteristic S gene target failure SGTF causing deletion D69 70 by which many qPCR tests have been able to rapidly detect a case as an Omicron or Alpha variant from the previously dominant Delta variant 285 286 Thus countries which primarily rely on SGTF for detection may overlook BA 2 285 and British authorities consider SGTF alone as insufficient for monitoring the spread of Omicron 272 This has resulted in it having been nicknamed Stealth Omicron 272 but because BA 2 still can be separated from other variants through normal full sequencing or checks of certain other mutations the nickname is not quite accurate 140 287 As of January 2022 some countries such as Denmark and Japan have been using a variant qPCR which tests for several mutations including L452R 282 161 It can also distinguish Delta which has L452R 288 and all Omicron subvariants which do not have L452R 289 147 As Omicron became dominant and the Delta variant became rare in early 2022 the SGTF mutation that had made Delta and BA 2 similar in qPCR tests was found to be useful for separating BA 1 and BA 2 from each other 290 Treatment editSee also Treatment and management of COVID 19 As of 28 November 2021 Corticosteroids such as dexamethasone and IL6 receptor blockers such as tocilizumab Actemra were known to be effective for managing patients with the earlier strains of severe COVID 19 but the impact on the effectiveness of other treatments was being assessed 291 292 Relating to monoclonal antibodies mAbs treatments similar testing and research is ongoing Preclinical data on in vitro pseudotyped virus data demonstrate that some mAbs designed to use highly conserved epitopes retain neutralizing activity against key mutations of Omicron substitutions 293 Similar results are confirmed by cryo electron microscopy and X ray data also providing the structural approach and molecular basis for the evasion of humoral immunity exhibited by Omicron antigenic shift as well as the importance of targeting conserved epitopes for vaccine and therapeutics design While 7 clinical mAbs or mAb cocktails experienced loss of neutralizing activity of 1 2 orders of magnitude or greater relative to the prototypic virus the S309 mAb the parent mAb of sotrovimab neutralized Omicron with only 2 3 fold reduced potency 294 As of December 2021 most monoclonal antibodies had lost in vitro neutralizing activity against Omicron with only 3 out of 29 mAbs examined in another study retaining unaltered potency Furthermore a fraction of broadly neutralizing sarbecovirus mAbs neutralized Omicron through recognition of antigenic sites outside the RBM including sotrovimab VIR 7831 S2X259 and S2H97 295 However sotrovimab was not fully active against the BA 2 Omicron sublineage and in March 2022 the office of the U S ASPR stopped distributing the antibody treatment to states where BA 2 was dominant 296 February 2022 data suggested Omicron caused significant humoral immune evasion while neutralizing antibodies targeting the sarbecovirus conserved region remained most effective 297 Epidemiology editOn 26 November 2021 the South African National Institute for Communicable Diseases announced that 30 904 COVID 19 tests in one day detected 2 828 new COVID 19 infections a 9 2 positivity rate 298 One week later on 3 December 2021 the NICD announced that 65 990 COVID 19 tests had found 16 055 new infections 5 7 times as many as seven days before positive rate 24 3 and that 72 percent of them were found in Gauteng 299 300 This province of South Africa is densely populated at about 850 inhabitants per km2 Gauteng s capital Johannesburg is a megacity about 5 5 million inhabitants in the city itself plus 9 5 million in the urban region citation needed In November 2021 the transmissibility of the Omicron variant as compared to the Delta variant or other variants of the COVID 19 virus was still uncertain 291 Omicron is frequently able to infect previously COVID 19 positive people 301 302 It has been estimated the Omicron variant diverged in late September or early October 2021 based on Omicron genome comparisons 303 Sequencing data suggests that Omicron had become the dominant variant in South Africa by November 2021 the same month where it had been first identified in the country 304 305 Phylogeny suggests a recent emergence Data from South Africa suggests that Omicron has a pronounced growth advantage there However this may be due to transmissibility or immune escape related or both 306 Also the serial interval plays a role in the growth Detectable changes in levels of COVID 19 in wastewater samples from South Africa s Gauteng province were seen as early as 17 23 October week 42 307 The National Institute for Communicable Diseases reports that children under the age of 2 make up 10 of total hospital admissions in the Omicron point of discovery Tshwane in South Africa 308 Data on the S gene target failure SGTF of sampled cases in South Africa indicates a growth of 21 per day relative to Delta generating an increased reproduction number by a factor of 2 4 a Omicron became the majority strain in South Africa around 10 November 309 310 Another analysis showed 32 growth per day in Gauteng South Africa having become dominant there around 6 November 311 In the UK the logarithmic growth rate of Omicron associated S gene target failure SGTF cases over S gene target positive SGTP cases was estimated at 0 37 per day b which is exceptionally high 312 Furthermore by 14 December it appears to have become the most dominant strain c 313 Without presuming behavior change in response to the variant a million infections per day by 24 December are projected for a 2 5 days doubling time d 281 In Denmark the growth rate has been roughly similar with a doubling time of about 2 3 days it having become the most prevalent strain on 17 December 314 315 316 Switzerland is not far behind 317 In Germany Omicron became the most prevalent variant on 1 January 318 In Scotland Omicron apparently became the most prevalent variant on 17 December 319 320 In the Canadian province of Ontario it became the most prevalent strain on 13 December 321 In the US the variant appears to have become the most prevalent strain on 18 December growing at 0 24 per day 322 In Portugal Omicron had reached 61 5 of cases on 22 December 323 In Belgium the strain has become the most prevalent on 25 December 324 and in the Netherlands on 28 December 325 In Italy it had reached 28 of cases on 20 December and was doubling every two days 326 while it became the dominant variant in Norway on 25 December 327 In France it made up about 15 of COVID 19 cases in mid December but around 27 December it had increased to more than 60 328 329 Researchers recommend sampling at least 5 of COVID 19 patient samples in order to detect Omicron or other emerging variants 330 During January 2022 in Denmark the BA 2 variant grew at 0 10 per day 11 per day as a ratio to BA 1 the legacy Omicron variant and became the dominant strain in week 2 2022 164 In the United Kingdom the BA 2 variant was growing at 0 11 per day 12 per day as a ratio to BA 1 331 On 13 January 2022 the BBC reported that the hospitalization rate was higher in the US and Canada than in Europe and South Africa This was attributed to a combination of a greater number of elderly people than in South Africa greater prevalence of comorbidities such as hypertension and obesity than in Europe higher indoor transmission due to the winter lower vaccination rate in the US than in Europe and Canada and a possible still high prevalence of the Delta variant which more often leads to hospitalization 332 Reported cases edit Confirmed and suspected cases by country and territory viewtalkedit Country Territory Confirmed cases PANGOLIN 333 as of 5 May 2022 Confirmed cases GISAID 334 as of July 29 2022 Confirmed cases other sources As of 24 June 2022 update Suspected cases nbsp United States 999 565 1 431 772 62 480 335 As of January 8 2022 update nbsp United Kingdom 999 565 1 253 700 246 780 336 600 041 336 nbsp Germany 207 407 365 837 268 661 337 nbsp Austria 6 809 57 379 290 378 338 339 nbsp Denmark 196 746 264 998 66 563 340 nbsp France 83 564 184 880 5 591 341 nbsp Canada 73 584 147 223 174 248 342 nbsp Japan 67 203 153 110 12 453 343 nbsp India 37 542 81 017 8 209 344 345 nbsp Australia 33 905 80 013 11 071 346 nbsp Norway 14 729 24 529 45 296 283 nbsp Thailand 6 778 12 811 5 397 347 nbsp Indonesia 9 761 12 028 3 779 348 nbsp Singapore 4 543 7 300 4 322 349 350 351 352 nbsp Estonia 1 982 3 778 3 857 353 354 355 nbsp Israel 22 164 60 435 1 741 356 357 861 356 nbsp South Africa 9 631 16 451 1 095 358 19 070 359 nbsp South Korea 7 731 27 705 1 318 360 nbsp Spain 24 607 31 992 51 337 361 nbsp Belgium 26 448 30 865 121 338 361 nbsp Sweden 38 397 42 525 53 760 362 nbsp Switzerland 30 034 32 635 19 269 338 363 nbsp Argentina 2 228 2 583 455 364 365 80 366 nbsp Botswana 931 1 594 23 367 nbsp Netherlands 24 381 26 601 123 368 361 nbsp Ireland 24 654 29 518 29 576 369 nbsp Gibraltar 112 122 24 370 nbsp Iceland 84 371 nbsp Italy 23 707 27 292 84 372 nbsp Chile 4 097 4 572 684 373 374 375 nbsp Portugal 7 683 8 870 69 376 361 6 377 338 nbsp Morocco 128 138 76 378 246 378 nbsp Zimbabwe 185 219 50 379 nbsp Ghana 441 605 33 367 nbsp Brazil 27 787 32 224 203 380 nbsp Finland 4 029 5 239 523 381 382 nbsp Cyprus 31 383 384 nbsp Kenya 1 653 2 329 27 385 nbsp Russia 1 273 1 738 8 239 386 nbsp Cayman Islands 44 387 59 387 nbsp Uganda 12 38 25 388 389 nbsp Mexico 12 736 13 678 1 390 nbsp New Zealand 3 169 3 739 116 391 nbsp Namibia 125 213 18 392 nbsp Hong Kong 1 432 3 526 102 393 394 nbsp Senegal 14 229 3 395 nbsp Mozambique 133 176 2 396 2 335 nbsp Greece 3 268 3 276 17 338 397 nbsp Bermuda 24 144 398 399 nbsp Latvia 407 407 644 400 361 401 nbsp Romania 4 034 4 282 25 402 403 404 nbsp Malaysia 5 330 7 353 245 405 nbsp Zambia 141 365 11 406 nbsp Nigeria 827 1 638 6 407 nbsp Czech Republic 13 264 15 147 10 338 408 361 nbsp Kosovo 245 262 9 409 nbsp Slovenia 15 684 17 106 1 418 410 361 411 412 nbsp Lebanon 85 107 433 413 414 16 413 nbsp Reunion 2 014 2 402 2 415 nbsp Mauritius 763 7 335 nbsp Poland 31 766 33 327 1 416 nbsp Rwanda 70 178 6 416 nbsp Turkey 9 135 10 239 6 417 nbsp Montenegro 142 211 5 418 nbsp Cambodia 950 974 31 419 nbsp Peru 5 653 5 960 10 032 420 nbsp Jordan 83 83 832 421 nbsp China 96 96 4 422 423 424 nbsp Cuba 92 425 426 427 nbsp Croatia 10 379 11 742 3 338 nbsp Egypt 15 40 3 416 nbsp Malawi 133 166 3 428 nbsp Palestinian Territory 5 9 126 429 430 nbsp Taiwan 34 34 89 431 nbsp Lithuania 7 063 9 136 2 432 nbsp Colombia 1 629 3 816 3 433 nbsp Slovakia 13 501 15 625 3 434 nbsp Trinidad and Tobago 291 499 1 435 nbsp Puerto Rico 3 166 3 558 1 436 nbsp Fiji 2 437 nbsp Nepal 255 349 2 438 nbsp Myanmar 25 28 4 439 nbsp Philippines 1 281 1 549 535 440 441 442 443 444 445 nbsp Northern Cyprus 9 446 nbsp Bangladesh 690 998 10 447 nbsp Liechtenstein 246 736 1 448 3 335 nbsp Hungary 28 28 61 449 361 450 nbsp Oman 71 85 2 451 nbsp Pakistan 359 463 75 452 453 nbsp Sri Lanka 626 927 1 454 nbsp Georgia country 718 822 600 455 nbsp Algeria 61 73 1 416 nbsp Bahrain 1 456 nbsp Ecuador 1 177 1 561 1 457 nbsp Kuwait 54 72 1 458 nbsp Luxembourg 4 031 11 149 1 338 nbsp Maldives 281 5 459 460 nbsp Sierra Leone 1 1 461 nbsp Saudi Arabia 28 30 1 462 nbsp Tunisia 51 52 1 463 nbsp United Arab Emirates 1 1 464 nbsp Iran 595 682 467 465 nbsp Ukraine 73 99 1 466 nbsp Panama 821 822 1 467 nbsp Costa Rica 1 430 1 529 1 468 nbsp Aruba 61 61 1 469 nbsp North Macedonia 46 47 9 470 471 nbsp Vietnam 1 085 1 790 108 472 nbsp Brunei 1 163 1 253 8 473 nbsp Malta 138 162 2 474 nbsp Venezuela 60 62 7 475 nbsp French Guiana 366 20 476 nbsp Republic of the Congo 50 78 1 477 nbsp Qatar 267 290 4 478 nbsp Paraguay 122 139 3 479 nbsp Burkina Faso 17 2 480 nbsp Curacao 482 487 1 481 nbsp Saint Kitts and Nevis 16 2 482 nbsp Libya 2 483 nbsp Albania 1 1 1 484 nbsp Barbados 1 7 1 485 nbsp Saint Vincent and the Grenadines 62 1 486 nbsp Dominican Republic 69 73 1 487 nbsp Jamaica 443 622 1 488 nbsp Serbia 81 81 1 489 nbsp Tanzania 2 3 1 490 nbsp Togo 5 491 nbsp Belarus 71 4 492 nbsp Bosnia and Herzegovina 118 122 10 493 nbsp Angola 25 37 16 494 nbsp Democratic Republic of the Congo 34 204 1 495 nbsp Bulgaria 2 516 2 520 12 496 nbsp Mayotte 123 130 1 497 nbsp Martinique 593 1 498 nbsp Gambia 30 155 26 499 nbsp Seychelles 235 464 500 nbsp Saint Martin 224 240 2 501 nbsp Laos 1 502 nbsp Iraq 36 103 5 503 nbsp Mauritania 14 504 nbsp South Sudan 28 28 41 505 nbsp Ivory Coast 41 60 78 506 nbsp Cape Verde 152 175 507 nbsp Antigua and Barbuda 36 1 508 nbsp Gabon 1 509 nbsp Bolivia 2 7 1 510 nbsp Moldova 287 314 29 511 nbsp Kazakhstan 8 8 8 512 nbsp Guadeloupe 264 300 1 513 nbsp Azerbaijan 12 12 12 514 nbsp Suriname 81 96 146 500 nbsp Sint Maarten 479 753 500 nbsp British Virgin Islands 20 26 39 500 nbsp Mali 1 2 nbsp Anguilla 20 24 30 500 nbsp Bonaire 400 692 500 nbsp Bhutan 14 515 nbsp Papua New Guinea 379 565 1 516 nbsp Mongolia 133 133 12 517 nbsp Antarctica 24 518 nbsp Uzbekistan 1 519 nbsp Saint Lucia 1 9 54 500 nbsp Burundi 1 28 500 nbsp American Samoa 35 84 500 nbsp Armenia 4 16 17 500 nbsp Guinea 48 167 159 500 nbsp Guam 168 274 348 500 nbsp Belize 223 240 441 500 nbsp Eswatini 124 133 nbsp Djibouti 306 308 337 500 World total 170 countries and territories 2 986 573 3 517 102 1 168 383 620 384See also edit nbsp COVID 19 portal nbsp Medicine portal nbsp Viruses portal nbsp Africa portalTimeline of the SARS CoV 2 Omicron variant Variants of SARS CoV 2 Other variants of either interest or concern Alpha Beta Gamma Delta Epsilon Zeta Eta Theta Iota Kappa Lambda Mu Sikhulile Moyo scientist who discovered SARS CoV 2 OmicronNotes edit With a presumed identical person to person serial interval of loge 2 4 0 21 4 2 days or a distribution thereof to the same effect Logarithmic growth rate of 0 37 day means that the log odds loge SGTF SGTP is increasing by 0 37 in a day So SGTF SGTP was increasing by a multiplicative factor of exp 0 37 1 45 This is substantially higher than a naive increase to 100 37 The difference is mathematically due to compound growth within the day which does not imply that epidemically people are already infectious within a day Rather simplified non delay differential equations are used for convenience for the modeling This also indicates a doubling time of loge 2 0 37 day 1 days for the Omicron to Delta prevalence ratio Referring to ref 12 in the reference where the x axis is crossed at 14 December A doubling time of 2 5 days corresponds to an exponential growth rate of ln 2 2 5 days 0 28 day Direct comparison to the logistic growth rate needs to take the growth decline of Delta into account References edit a b c Yadav PD Gupta N Potdar V Mohandas S Sahay RR Sarkale P et al January 2022 An in vitro and in vivo approach for the isolation of Omicron variant from human clinical specimens pp 2022 01 02 474750 doi 10 1101 2022 01 02 474750 Archived from the original on 16 January 2022 Retrieved 16 January 2022 a b Padin M 17 January 2022 Feeling light headed may be an early indication you have Omicron Covid variant Daily Mirror Archived from the original on 28 January 2022 Retrieved 30 January 2022 Poudel S Ishak A Perez Fernandez J Garcia E Leon Figueroa DA Romani L et al December 2021 Highly mutated SARS CoV 2 Omicron variant sparks significant concern among global experts What is known so far Travel Medicine and Infectious Disease 45 102234 doi 10 1016 j tmaid 2021 102234 PMC 8666662 PMID 34896326 a b c d Adams R 24 December 2021 Omicron s cold like symptoms mean UK guidance needs urgent update The Guardian Archived from the original on 25 December 2021 a b Omicron Symptoms Here s How They Differ From Other Variants NBC Chicago 7 January 2022 Archived from the original on 24 January 2022 Retrieved 30 January 2022 a b Slater Jack 23 January 2022 Is a change to your taste or smell a sign of Omicron Metro Archived from the original on 26 January 2022 Retrieved 30 January 2022 a b Scribner H 21 December 2021 Doctor reveals new nightly omicron variant symptom Deseret News Archived from the original on 2 January 2022 Retrieved 1 January 2022 Does Omicron cause less damage to the lungs medicalnewstoday com 14 January 2022 Retrieved 22 August 2023 Murrison P 18 January 2022 Omicron symptoms Three distinctive rashes to watch for Express co uk Archived from the original on 12 January 2022 Retrieved 30 January 2022 a b c Quarleri J Galvan V Delpino MV February 2022 Omicron variant of the SARS CoV 2 a quest to define the consequences of its high mutational load GeroScience 44 1 53 56 doi 10 1007 s11357 021 00500 4 PMC 8683309 PMID 34921354 Gowrisankar A Priyanka TM Banerjee S 10 January 2022 Omicron a mysterious variant of concern European Physical Journal Plus 137 1 100 Bibcode 2022EPJP 137 100G doi 10 1140 epjp s13360 021 02321 y PMC 8743750 PMID 35036269 a b Vitiello A Ferrara F Auti AM Di Domenico M Boccellino M July 2022 Advances in the Omicron variant development Journal of Internal Medicine 292 1 81 90 doi 10 1111 joim 13478 PMC 9115048 PMID 35289434 a b Yao L Zhu KL Jiang XL Wang XJ Zhan BD Gao HX et al June 2022 Omicron subvariants escape antibodies elicited by vaccination and BA 2 2 infection The Lancet Infectious Diseases 22 8 1116 1117 doi 10 1016 s1473 3099 22 00410 8 PMC 9212811 PMID 35738299 Ahmed SF Quadeer AA McKay MR January 2022 SARS CoV 2 T Cell Responses Elicited by COVID 19 Vaccines or Infection Are Expected to Remain Robust against Omicron Viruses 14 1 79 doi 10 3390 v14010079 PMC 8781795 PMID 35062283 Al Jurdi A Gassen RB Borges TJ Lape IT Morena L Efe O et al June 2022 Suboptimal antibody response against SARS CoV 2 Omicron variant after third dose of mRNA vaccine in kidney transplant recipients pp 1282 1286 medRxiv 10 1101 2022 01 03 22268649v1 Altarawneh HN Chemaitelly H Ayoub HH Tang P Hasan MR Yassine HM et al July 2022 Effects of Previous Infection and Vaccination on Symptomatic Omicron Infections The New England Journal of Medicine 387 1 21 34 doi 10 1056 NEJMoa2203965 PMC 9258753 PMID 35704396 S2CID 249677809 Nemet I Kliker L Lustig Y Zuckerman N Erster O Cohen C et al February 2022 Third BNT162b2 Vaccination Neutralization of SARS CoV 2 Omicron Infection The New England Journal of Medicine 386 5 492 494 doi 10 1056 NEJMc2119358 PMC 8823651 PMID 34965337 Cao Y Yisimayi A Jian F Song W Xiao T Wang L et al June 2022 BA 2 12 1 BA 4 and BA 5 escape antibodies elicited by Omicron infection Nature 608 7923 593 602 Bibcode 2022Natur 608 593C doi 10 1038 s41586 022 04980 y PMC 9385493 PMID 35714668 Hachmann NP Miller J Collier AY Ventura JD Yu J Rowe M et al July 2022 Neutralization Escape by SARS CoV 2 Omicron Subvariants BA 2 12 1 BA 4 and BA 5 The New England Journal of Medicine 387 1 86 88 doi 10 1056 NEJMc2206576 PMC 9258748 PMID 35731894 S2CID 249956777 Patel V 27 November 2021 How Omicron the New Covid 19 Variant Got Its Name The New York Times ISSN 0362 4331 Archived from the original on 28 November 2021 Retrieved 28 November 2021 Tcholakian D 15 December 2021 Omni is everywhere why do so many people struggle to say Omicron The Guardian Archived from the original on 23 December 2021 Retrieved 23 December 2021 Zimmer B 2 December 2021 Omicron Greek s Little O Will Loom Larger Now Wall Street Journal ISSN 0099 9660 Archived from the original on 3 December 2021 Retrieved 23 December 2021 President Joe Biden stumbled over the pronunciation in a press conference on Monday calling the variant omnicron with an extra n sound It has also been frequently misspelled that way online The confusion is understandable since we re more familiar with words that have the Latin prefix omni meaning all as in omnipresent or omnivore In focus gisaid org GISAID 28 November 2021 Archived from the original on 21 January 2021 Retrieved 28 November 2021 The unique mix of spike amino acid changes in Omicron GR 484A B 1 1 529 is of interest as it comprises several that were previously known to affect receptor binding and antibody escape a b Variant 21K Omicron covariants org CoVariants 28 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 Variant 21K Omicron appears to have arisen in November 2021 possibly in South Africa a b Viana R Moyo S Amoako DG Tegally H Scheepers C Althaus CL et al March 2022 Rapid epidemic expansion of the SARS CoV 2 Omicron variant in southern Africa Nature 603 7902 679 686 Bibcode 2022Natur 603 679V doi 10 1038 s41586 022 04411 y PMC 8942855 PMID 35042229 Dyer O December 2021 Covid 19 South Africa s surge in cases deepens alarm over omicron variant BMJ 375 n3013 doi 10 1136 bmj n3013 PMID 34862184 S2CID 244842008 a b Gu H Krishnan P Ng DY Chang LD Liu GY Cheng SS et al February 2022 Probable Transmission of SARS CoV 2 Omicron Variant in Quarantine Hotel Hong Kong China November 2021 Emerging Infectious Diseases 28 2 460 462 doi 10 3201 eid2802 212422 PMC 8798678 PMID 34860154 a b Planas D Saunders N Maes P Guivel Benhassine F Planchais C Buchrieser J et al February 2022 Considerable escape of SARS CoV 2 Omicron to antibody neutralization Nature 602 7898 671 675 Bibcode 2022Natur 602 671P doi 10 1038 s41586 021 04389 z PMID 35016199 S2CID 256823009 a b Saxena SK Kumar S Ansari S Paweska JT Maurya VK Tripathi AK Abdel Moneim AS May 2022 Transmission dynamics and mutational prevalence of the novel Severe acute respiratory syndrome coronavirus 2 Omicron Variant of Concern Journal of Medical Virology 94 5 2160 2166 doi 10 1002 jmv 27611 PMC 9015611 PMID 35050521 a b Wei C Shan KJ Wang W Zhang S Huan Q Qian W December 2021 Evidence for a mouse origin of the SARS CoV 2 Omicron variant Journal of Genetics and Genomics Yi Chuan Xue Bao 48 12 1111 1121 doi 10 1016 j jgg 2021 12 003 PMC 8702434 PMID 34954396 a b Alkhatib M Salpini R Carioti L Ambrosio FA D Anna S Duca L et al April 2022 Perez DR ed Update on SARS CoV 2 Omicron Variant of Concern and Its Peculiar Mutational Profile Microbiology Spectrum 10 2 e0273221 doi 10 1128 spectrum 02732 21 PMC 9045195 PMID 35352942 a b c Tarcsai KR Corolciuc O Tordai A Ongradi J June 2022 SARS CoV 2 infection in HIV infected patients potential role in the high mutational load of the Omicron variant emerging in South Africa GeroScience 44 5 2337 2345 doi 10 1007 s11357 022 00603 6 PMC 9225796 PMID 35739343 The mystery of where omicron came from and why it matters NPR 1 December 2021 Archived from the original on 9 December 2021 Retrieved 8 December 2021 Zungu N Mabaso M Ramlagan S Simbayi L Moyo S Shisana O et al May 2022 Is There Risk Compensation among HIV Infected Youth and Adults 15 Years and Older on Antiretroviral Treatment in South Africa Findings from the 2017 National HIV Prevalence Incidence Behaviour and Communication Survey International Journal of Environmental Research and Public Health 19 10 6156 doi 10 3390 ijerph19106156 PMC 9141949 PMID 35627693 Fischer Carlo et al 2022 Gradual emergence followed by exponential spread of the SARS CoV 2 Omicron variant in Africa Science 378 6623 eadd8737 doi 10 1126 science add8737 PMID 36454863 S2CID 254150265 Mallapaty Smriti 6 December 2022 Surprising Omicron origins study comes under scrutiny Nature 612 7940 387 388 Bibcode 2022Natur 612 387M doi 10 1038 d41586 022 04357 1 PMID 36474049 S2CID 254402519 Study on the origins of Omicron retracted www charite de 20 December 2022 Retrieved 24 December 2022 In a subsequent analysis of residual samples they were found to be contaminated It is no longer possible to establish the source of the contamination We made a mistake Omicron origin study retracted after widespread criticism science org 20 December 2022 Retrieved 24 December 2022 But Kristian Andersen says the gradual evolution theory was already off the table before the paper was published Cowan K 29 November 2021 Inside SA leg of Omicron variant discovery A single test result a missing gene and an email News24 Archived from the original on 2 December 2021 Retrieved 2 December 2021 a b Callaway E December 2021 Heavily mutated Omicron variant puts scientists on alert Nature 600 7887 21 Bibcode 2021Natur 600 21C doi 10 1038 d41586 021 03552 w PMID 34824381 S2CID 244660616 Archived from the original on 26 November 2021 Retrieved 26 November 2021 a b BNODesk 26 November 2021 Statement from Israel s health ministry reporting 1 confirmed case of new coronavirus variant B 1 1 529 Tweet Retrieved 26 November 2021 via Twitter ינקו אדיר שומפלבי אטילה 26 November 2021 מחוסנת ב 3 מנות ואישה שנסעה לאילת באוטובוס המאומתים לזן החדשt Ynet in Hebrew Archived from the original on 27 November 2021 Retrieved 28 November 2021 4 מאומתים לווריאנט החדש התגלו בארץ רה מ יקיים מסיבת עיתונאים ב 14 30 translated 4 verified for the new variant were discovered in the country the prime minister will hold a press conference at 14 30 Four cases of the new COVID 19 variant recorded in Botswana Archived 26 November 2021 at the Wayback Machine 25 November 2021 Mmegi Online accessed 26 November 2021 Kesselgruber K 27 November 2021 Flughafen Frankfurt Person mit Omikron Verdacht war vollstandig geimpft Frankfurt airport Person suspected to be infected with Omicron Variant was fully vaccinated Frankfurter Rundschau in German Archived from the original on 27 November 2021 Retrieved 27 November 2021 UK Germany and Italy detect Omicron coronavirus variant cases Reuters 27 November 2021 Archived from the original on 27 November 2021 Retrieved 27 November 2021 Coronavirus variant Omicron found in 13 positive tests so far RIVM www rivm nl Archived from the original on 6 December 2021 Retrieved 6 December 2021 Actuele informatie over COVID 19 RIVM Current information about COVID 19 RIVM www rivm nl in Dutch 4 December 2021 Archived from the original on 6 April 2020 Retrieved 6 December 2021 61 travellers from South Africa in Netherlands positive for COVID 19 authorities Reuters Amsterdam 27 November 2021 Archived from the original on 26 November 2021 Retrieved 27 November 2021 Travellers test positive to Omicron COVID 19 strain after arriving in Sydney from southern Africa NSW Health says ABC News 28 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 To personer er indrejst i Danmark med coronavarianten Omikron Two people have entered Denmark with the corona variant Omicron www bt dk in Danish 28 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 Ritzau A 28 November 2021 Nu er det bekraeftet To personer smittet med Omikron rejst ind i Danmark Now it has been confirmed Two people infected with Omicron traveled into Denmark ekstrabladet dk in Danish Archived from the original on 28 November 2021 Retrieved 28 November 2021 Austria detects suspect Omicron case as Europe battles virus surge WION Archived from the original on 28 November 2021 Retrieved 28 November 2021 Omicron variant found in UK Germany Czech Republic New York Post 28 November 2021 Archived from the original on 27 November 2021 Retrieved 28 November 2021 Canada Netherland Australia latest countries reporting cases of omicron COVID 19 variant ABC13 28 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 Perera A 29 November 2021 COVID positive repatriation flight arrival to the Northern Territory tests positive to Omicron variant ABC News Archived from the original on 29 November 2021 Retrieved 29 November 2021 Nguyen K 29 November 2021 NSW Health confirms two more Omicron COVID 19 cases in travellers from southern Africa ABC News Archived from the original on 29 November 2021 Retrieved 29 November 2021 Live updates Omicron variant Cable News Network 29 November 2021 Archived from the original on 30 November 2021 Retrieved 29 November 2021 Forsta fallet av omikron upptackt i Sverige The first case of omicron detection in Sweden www aftonbladet se in Swedish 29 November 2021 Archived from the original on 30 November 2021 Retrieved 29 November 2021 Spain detects first Omicron case COVID 19 infections rise Reuters 29 November 2021 Archived from the original on 30 November 2021 Retrieved 30 November 2021 Omicron variant found in two previous test samples RIVM www rivm nl Archived from the original on 4 December 2021 Retrieved 6 December 2021 NSW records fifth case of Omicron COVID 19 variant as two more potential infections investigated ABC News 30 November 2021 Archived from the original on 30 November 2021 Retrieved 30 November 2021 Japan s first Omicron case may help portray PM Kishida as decisive Reuters 30 November 2021 Archived from the original on 30 November 2021 Retrieved 30 November 2021 Two Israeli doctors test positive for Omicron COVID variant The Jerusalem Post 30 November 2021 Archived from the original on 31 December 2021 Retrieved 30 November 2021 SP confirma terceiro caso da variante omicron SP confirms third case of omicron variant g1 in Brazilian Portuguese 1 December 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 O que se sabe sobre os primeiros casos confirmados da variante Omicron no Brasil What is known about the first confirmed cases of the Omicron variant in Brazil CNN Brasil in Brazilian Portuguese 30 November 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 Passa para 6 o numero de casos suspeitos da variante Omicron investigados no Brasil The number of suspected cases of the Omicron variant investigated in Brazil goes to 6 CNN Brasil in Brazilian Portuguese 30 November 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 Germany Leipzig reports first Omicron variant case with no travel history Free Press Journal Archived from the original on 1 December 2021 Retrieved 1 December 2021 Dahir A Ezeamalu B Perez Pena R 1 December 2021 Ghana and Nigeria are the latest African countries to detect the Omicron variant The New York Times Archived from the original on 2 December 2021 Retrieved 2 December 2021 Nigeria confirms first cases of Omicron among travellers from South Africa Reuters 1 December 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 Graff A 1 December 2021 First case of omicron in US identified in San Francisco San Francisco Chronicle Archived from the original on 1 December 2021 Retrieved 1 December 2021 Stark K Rodriguez JF Dillon RM 1 December 2021 First U S Case of Omicron Variant Found in San Francisco Resident San Francisco KQED Archived from the original on 1 December 2021 Retrieved 1 December 2021 O Donnell D 1 December 2021 Case of Omicron variant confirmed in Ireland RTE News and Current Affairs Archived from the original on 3 December 2021 Retrieved 12 December 2021 South Korea reports five Omicron cases on flight from Nigeria Reuters 1 December 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 Dutch say 14 air passengers from S Africa with Omicron were vaccinated Reuters 2 December 2021 Archived from the original on 2 December 2021 Retrieved 2 December 2021 Number of confirmed omicron cases as of 3 December Folkehelseinstituttet 4 December 2021 Archived from the original on 4 December 2021 Retrieved 4 December 2021 France now has 25 Omicron Covid variant cases minister Reuters 6 December 2021 Archived from the original on 6 December 2021 Retrieved 7 December 2021 Omicron sudah sampai ke Malaysia Malaysiakini 3 December 2021 Archived from the original on 3 December 2021 Retrieved 8 December 2021 Namibia detects Omicron coronavirus variant in 18 of 19 samples Reuters 6 December 2021 Archived from the original on 6 December 2021 Retrieved 7 December 2021 Fijians test positive for Omicron variant Govt RNZ 7 December 2021 Archived from the original on 6 December 2021 Retrieved 8 December 2021 Africa accounts for 46 of reported cases of Omicron WHO official says Reuters 9 December 2021 Archived from the original on 10 December 2021 Retrieved 9 December 2021 Covid First UK death recorded with Omicron variant BBC News 13 December 2021 Archived from the original on 20 December 2021 Retrieved 13 December 2021 First Omicron case detected in New Zealand Ministry of Healfh 16 December 2021 Archived from the original on 20 December 2021 Retrieved 16 December 2021 COVID Germany records first death from omicron variant DW 23 December 2021 Archived from the original on 24 December 2021 Retrieved 23 December 2021 Australia Omicron death false negative COVID results Al Jazeera 27 December 2021 Archived from the original on 27 December 2021 Retrieved 27 December 2021 U S CDC estimates Omicron variant to be 58 6 of cases revises projection Reuters 28 December 2021 Retrieved 15 April 2022 S Korea reports first deaths linked to Omicron coronavirus variant Yonhap Reuters 3 January 2022 Archived from the original on 3 January 2022 Retrieved 3 January 2022 a b Statement on the update of WHO s working definitions and tracking system for SARS CoV 2 variants of concern and variants of interest Statement World Health Organization 16 March 2023 Retrieved 20 May 2023 Goodman Brenda 29 March 2022 Omicron subvariant BA 2 is now the dominant strain of Covid 19 in the US CDC says CNN Retrieved 29 March 2022 McDade Aaron 29 March 2022 Omicron BA 2 sub variant now dominant in U S CDC says Newsweek Retrieved 29 March 2022 CDC 28 March 2020 COVID Data Tracker Centers for Disease Control and Prevention Retrieved 29 March 2022 Gretchen Vogel 22 May 2022 New versions of Omicron are masters of immune evasion Science BioNTech says it could tweak Covid vaccine in 100 days if needed The Guardian 26 November 2021 Archived from the original on 27 November 2021 Retrieved 27 November 2021 Novavax developing vaccine that targets new COVID 19 variant CBS Baltimore Staff 30 November 2021 Archived from the original on 2 December 2021 Retrieved 4 December 2021 Maddipatla M Roy M 26 November 2021 Maryland Based Vaccine Manufacturer Developing COVID 19 Vaccine That Targets Omicron Variant Reuters Archived from the original on 28 November 2021 Retrieved 30 November 2021 Sputnik V maker Vaccine could be adapted to fight omicron ABC News Moscow Associated Press 29 November 2021 Archived from the original on 2 December 2021 Retrieved 29 November 2021 Sinovac and world s Covid 19 vaccine makers ready to produce Omicron jab South China Morning Post 29 November 2021 Archived from the original on 30 November 2021 Retrieved 29 November 2021 Sinovac preve atualizacao da Coronavac para variante Omicron em ate tres meses Sinovac plans to update Coronavac to the Omicron variant within three months CNN Brazil in Portuguese 7 December 2021 Archived from the original on 9 December 2021 Retrieved 9 December 2021 Cuba to update domestic vaccine to battle Omicron Al Jazeera 2 December 2021 Archived from the original on 20 December 2021 Retrieved 20 December 2021 Spencer K 10 January 2022 Pfizer CEO says omicron vaccine will be ready in March CNBC Archived from the original on 26 January 2022 Retrieved 27 January 2022 Classification of Omicron B 1 1 529 SARS CoV 2 Variant of Concern WHO 26 November 2021 Archived from the original on 26 November 2021 WHO cautions against imposing travel restrictions due to new variant Reuters Geneva 26 November 2021 Archived from the original on 26 November 2021 Retrieved 26 November 2021 Implications of the emergence and spread of the SARS CoV 2 B 1 1 529 variant of concern Omicron for the EU EEA PDF ecdc europa eu Archived PDF from the original on 26 November 2021 Retrieved 26 November 2021 a b Classification of Omicron B 1 1 529 SARS CoV 2 Variant of Concern World Health Organization 26 November 2021 Archived from the original on 26 November 2021 Retrieved 26 November 2021 Nebehay S Winning A 26 November 2021 WHO names new COVID variant omicron cautions against travel measures Reuters Archived from the original on 26 November 2021 Retrieved 26 November 2021 a b Omicron poses very high global risk world must prepare WHO Reuters Geneva 29 November 2021 Archived from the original on 30 November 2021 Retrieved 30 November 2021 Covid live updates today Omicron variant symptoms vaccines efficacy restrictions en as 28 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 World closing its doors to African countries due to omicron aa com 30 November 2021 Archived from the original on 30 November 2021 Retrieved 30 November 2021 Yong C 26 November 2021 Singapore bans travellers from 7 African countries no cases of new Covid 19 variant here The Straits Times Singapore Archived from the original on 26 November 2021 Retrieved 26 November 2021 Anvisa recomenda restricoes de voo diante de nova variante de covid 19 Anvisa recommends flight restrictions in view of the new covid 19 variant agenciabrasil ebc com br 26 November 2021 Archived from the original on 26 November 2021 Retrieved 27 November 2021 Kennedy M Price RD 26 November 2021 It s Coming NY Declares State of Emergency Ahead of Potential Omicron Spike NBC New York Archived from the original on 26 November 2021 Retrieved 27 November 2021 Switzerland announces new restrictions for Israelis after the discovery of Omicron Globally 24 Archived from the original on 27 November 2021 Retrieved 27 November 2021 Winning A Cocks T 26 November 2021 South Africa says travel bans over new variant unjustified Reuters Archived from the original on 26 November 2021 Retrieved 26 November 2021 Zwi A 28 November 2021 Travel bans aren t the answer to stopping new COVID variant Omicron The Conversation Archived from the original on 28 November 2021 Retrieved 28 November 2021 EXCLUSIVE South Africa delays COVID vaccine deliveries as inoculations slow Reuters 24 November 2021 Archived from the original on 28 November 2021 Retrieved 28 November 2021 Kaitlan Collins and Kate Sullivan 29 November 2021 Biden says new Omicron variant is cause for concern not a cause for panic CNN Archived from the original on 2 December 2021 Retrieved 1 December 2021 New COVID 19 restrictions in effect for parts of Canada some productions cancelled CTVNews 20 December 2021 Archived from the original on 20 December 2021 Retrieved 20 December 2021 B C enacts social gathering and event capacity limits as Omicron variant spreads Global News Archived from the original on 19 December 2021 Retrieved 18 December 2021 B C limits indoor gatherings cancels New Year s Eve events as Omicron picks up speed CBC News 17 December 2021 Archived from the original on 20 December 2021 Retrieved 17 December 2021 Quebec shutting down schools bars gyms tonight as COVID 19 cases soar CTV News Montreal 20 December 2021 Archived from the original on 20 December 2021 Retrieved 20 December 2021 Meijer BH van den Berg S 18 December 2021 Netherlands to go into strict Christmas lockdown Reuters Archived from the original on 2 January 2022 Retrieved 2 January 2022 As Omicron threatens a global surge some countries shorten COVID 19 booster timelines Reuters 20 December 2022 Archived from the original on 15 January 2022 Retrieved 15 January 2022 Gregg A 26 November 2021 Dow plunges more than 900 points as new coronavirus variant sends global markets reeling Washington Post Archived from the original on 26 November 2021 Retrieved 26 November 2021 Omicron cryptocurrency soars on new variant www msn com Archived from the original on 1 December 2021 Retrieved 1 December 2021 Davies P 26 November 2021 Bitcoin s price has slumped after a new COVID variant was found Why euronews Archived from the original on 27 November 2021 Retrieved 27 November 2021 South African markets sink on new Covid 19 variant Moneyweb 26 November 2021 Archived from the original on 27 November 2021 Retrieved 29 November 2021 Rand tanks as UK red lists South Africa again amid new Covid variant Archived from the original on 26 November 2021 Retrieved 29 November 2021 New variant sees Rand plummet eNCA enca com Archived from the original on 26 November 2021 Retrieved 29 November 2021 Omicron raises uncertainty around inflation says Powell BBC News 2 December 2021 Archived from the original on 1 December 2021 Retrieved 1 December 2021 Selection analysis identifies significant mutational changes in Omicron that are likely to influence both antibody neutralization and Spike function Part 1 of 2 5 December 2021 Cella Eleonora Benedetti Francesca Fabris Silvia Borsetti Alessandra Pezzuto Aldo Ciotti Marco Pascarella Stefano Ceccarelli Giancarlo Zella Davide Ciccozzi Massimo Giovanetti Marta 2021 SARS CoV 2 Lineages and Sub Lineages Circulating Worldwide A Dynamic Overview Chemotherapy 66 1 2 3 7 doi 10 1159 000515340 PMC 8089399 PMID 33735881 Khandia R Singhal S Alqahtani T Kamal MA El Shall NA Nainu F et al June 2022 Emergence of SARS CoV 2 Omicron B 1 1 529 variant salient features high global health concerns and strategies to counter it amid ongoing COVID 19 pandemic Environmental Research 209 112816 Bibcode 2022ER 209k2816K doi 10 1016 j envres 2022 112816 PMC 8798788 PMID 35093310 Hong Q Han W Li J Xu S Wang Y Xu C et al April 2022 Molecular basis of receptor binding and antibody neutralization of Omicron Nature 604 7906 546 552 Bibcode 2022Natur 604 546H doi 10 1038 s41586 022 04581 9 PMID 35228716 S2CID 247167987 Mileto D Micheli V Fenizia C Cutrera M Gagliardi G Mancon A et al December 2022 Reduced neutralization of SARS CoV 2 Omicron variant by BNT162b2 vaccinees sera a preliminary evaluation Emerging Microbes amp Infections 11 1 790 792 doi 10 1080 22221751 2022 2045878 PMC 8920392 PMID 35196967 Zhang L Mann M Syed ZA Reynolds HM Tian E Samara NL et al November 2021 Furin cleavage of the SARS CoV 2 spike is modulated by O glycosylation Proceedings of the National Academy of Sciences of the United States of America 118 47 e2109905118 Bibcode 2021PNAS 11809905Z doi 10 1073 pnas 2109905118 PMC 8617502 PMID 34732583 S2CID 242937417 Walls AC Park YJ Tortorici MA Wall A McGuire AT Veesler D April 2020 Structure Function and Antigenicity of the SARS CoV 2 Spike Glycoprotein Cell 181 2 281 292 e6 doi 10 1016 j cell 2020 02 058 PMC 7102599 PMID 32155444 span, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.