fbpx
Wikipedia

SARS-CoV-2 Delta variant

January 19, 2024

For lineage B.1.617.1, see SARS-CoV-2 Kappa variant.

This article is about a variant of the virus that causes COVID-19. It is not to be confused with the Deltacoronavirus grouping of coronavirus species that affects birds and non-human mammals.

The Delta variant (B.1.617.2) was[3][4] a variant of SARS-CoV-2, the virus that causes COVID-19. It was first detected in India on 5 October 2020. The Delta variant was named on 31 May 2021 and had spread to over 179 countries by 22 November 2021. The World Health Organization (WHO) indicated in June 2021 that the Delta variant was becoming the dominant strain globally.[5]

SARS-CoV-2 Variant
Scientifically accurate atomic model of the external structure of SARS-CoV-2. Each "ball" is an atom.
General details
Symptoms
Major variants

It has mutations in the gene encoding the SARS-CoV-2 spike protein[6] causing the substitutions T478K, P681R and L452R,[7][8] which are known to affect transmissibility of the virus as well as whether it can be neutralised by antibodies for previously circulating variants of the COVID-19 virus.[9] In August 2021, Public Health England (PHE) reported secondary attack rate in household contacts of non-travel or unknown cases for Delta to be 10.8% vis-à-vis 10.2% for the Alpha variant;[10] the case fatality rate for those 386,835 people with Delta is 0.3%, where 46% of the cases and 6% of the deaths are unvaccinated and below 50 years old.[11] Immunity from previous recovery[12][13] or COVID-19 vaccines are effective in preventing severe disease or hospitalisation from infection with the variant.[14]

On 7 May 2021, PHE changed their classification of lineage B.1.617.2 from a variant under investigation (VUI) to a variant of concern (VOC) based on an assessment of transmissibility being at least equivalent to B.1.1.7 (Alpha variant);[15] the UK's SAGE using May data estimated a "realistic" possibility of being 50% more transmissible.[16] On 11 May 2021, the WHO also classified this lineage VOC, and said that it showed evidence of higher transmissibility and reduced neutralisation. On 15 June 2021, the Centers for Disease Control and Prevention (CDC) declared Delta a variant of concern.[17]

The variant is thought to be partly responsible for India's deadly second wave of the pandemic beginning in February 2021.[18][19][20] It later contributed to a third wave in Fiji, the United Kingdom[21][22][23] and South Africa,[24] and the WHO warned in July 2021 that it could have a similar effect elsewhere in Europe and Africa.[25][24] By late July, it had also driven an increase in daily infections in parts of Asia,[26] the United States,[27] Australia, and New Zealand.[28]

Classification

The Delta variant has mutations in the gene encoding the SARS-CoV-2 spike protein[6] causing the substitutions D614G, T478K, P681R and L452R.[29][8] It is identified as the 21A, 21I, and 21J clades under the Nextstrain phylogenetic classification system.[30]

Names

The virus has also been referred to by the term "Indian Variant"[31] as it was originally detected in India. However, the Delta variant is only one of three variants of the lineage B.1.617, all of which were first detected in India.[32] At the end of May 2021, the WHO assigned the label Delta to lineage B.1.617.2 after introducing a new policy of using Greek letters for variants of concern and variants of interest.[33]

Other sublineages of B.1.617

There are three sublineages of lineage B.1.617 categorised so far.

B.1.617.1 (Kappa variant) was designated a Variant Under Investigation in April 2021 by Public Health England. Later in April 2021, two other variants B.1.617.2 and B.1.617.3 were designated as Variants Under Investigation. While B.1.617.3 shares the L452R and E484Q mutations found in B.1.617.1, B.1.617.2 lacks the E484Q mutation. B.1.617.2 has the T478K mutation, not found in B.1.617.1 and B.1.617.3.[34][35] Simultaneously, the ECDC released a brief maintaining all three sublineages of B.1.617 as VOI, estimating that a "greater understanding of the risks related to these B.1.617 lineages is needed before any modification of current measures can be considered".[36]

Mutations

  •  
    Amino acid mutations of SARS-CoV-2 Delta variant plotted on a genome map of SARS-CoV-2 with a focus on Spike[37]
Defining mutations in the
SARS-CoV-2 Delta variant
Gene Nucleotide Amino acid
ORF1b P314L
P1000L
Spike G142D
T19R
R158G
L452R
T478K
D614G
P681R
D950N
E156del
F157del
M I82T
N D63G
R203M
D377Y
ORF3a S26L
ORF7a V82A
T120I
Sources: CDC[38] Covariants.org[39]

The Delta/ B.1.617.2 genome has 13 mutations (15 or 17 according to some sources,[which?] depending on whether more common mutations are included) which produce alterations in the amino-acid sequences of the proteins it encodes.[40]

The list of spike protein mutations is: 19R, (G142D), Δ156-157, R158G, L452R, T478K, D614G, P681R, D950N according to GVN,[41] or T19R, G142D, del 156–157, R158G, L452R, T478K, D614G, P681R according to Genscript[42] Four of them, all of which are in the virus's spike protein code, are of particular concern:

  • D614G. The substitution at position 614, an aspartic acid-to-glycine substitution, is shared with other highly transmissible variants like Alpha, Beta and Gamma.[9]
  • T478K.[9][29] The exchange at position 478 is a threonine-to-lysine substitution.[43]
  • L452R. The substitution at position 452, a leucine-to-arginine substitution, confers stronger affinity of the spike protein for the ACE2 receptor[44] and decreased recognition capability of the immune system.[8][45]
  • P681R. The substitution at position 681, a proline-to-arginine substitution, which, according to William A. Haseltine, may boost cell-level infectivity of the variant "by facilitating cleavage of the S precursor protein to the active S1/S2 configuration".[46]

The E484Q mutation is not present in the B.1.617.2 genome.[46][47]

Lineages

As of August 2021, Delta variants have been subdivided in the Pango lineage designation system into variants from AY.1 to AY.28. However, there is no information on whether such classification correlates with biological characteristic changes of the virus.[48] It is said that, as of August 2021, AY.4 to AY.11 are predominant in the UK, AY.12 in Israel, AY.2, AY.3, AY.13, AY.14, AY.25 in the US, AY.20 in the US and Mexico, AY.15 in Canada, AY.16 in Kenya, AY.17 in Ireland and Northern Ireland, AY.19 in South Africa, AY.21 in Italy and Switzerland, AY.22 in Portugal, AY.24 in Indonesia, and AY.23 in Indonesia, Singapore, Japan, and South Korea.[49]

"Delta plus" variant

See also: Variants of SARS-CoV-2 § Delta (lineage B.1.617.2)

Delta with K417N originally corresponded to lineages AY.1 and AY.2,[50] subsequently also lineage AY.3,[51] and has been nicknamed "Delta plus" or "Nepal variant".[52] It has the K417N mutation,[53] which is also present in the Beta variant.[54] The exchange at position 417 is a lysine-to-asparagine substitution.[55]

As of mid-October 2021, the AY.3 variant accounted for a cumulative prevalence of approximately 5% in the United States, and 2% worldwide.[56] In mid-October the AY.4.2 Delta sublineage was expanding in England, and being monitored and assessed. It contains mutations A222V and Y145H in its spike protein,[57] not considered of particular concern. It has been suggested that AY.4.2 might be 10-15% more transmissible than the original Delta variant. Mid-October 2021, AY.4.2 accounted for an estimated 10% of cases, and has led to an additional growth rate rising to about 1% (10% of 10%) per generational time of five days or so. This additional growth rate would grow with increasing prevalence. Without AY.4.2 and no other changes, the number of cases in the UK would have been about 10% lower.[58] AY.4.2 grows about 15% faster per week.[59] In the UK it was reclassified as a "variant under investigation" (but not "of concern") in late October 2021.[60] In Denmark, after a drop in AY.4.2 cases, a new fast surge was detected and monitored, but was not yet considered a cause of concern.[61][62]

Symptoms

Main article: Symptoms of COVID-19

The most common symptoms may have changed from the most common symptoms previously associated with standard COVID-19. Infected people may mistake the symptoms for a bad cold and not realize they need to isolate. Common symptoms reported have been headaches, sore throat, a runny nose or a fever.[1][medical citation needed][2]

Prevention

See also: COVID-19 § Prevention, Oxford–AstraZeneca COVID-19 vaccine § Effectiveness, Pfizer–BioNTech COVID-19 vaccine § Effectiveness, Moderna COVID-19 vaccine § Effectiveness, Janssen COVID-19 vaccine § Clinical trials, Sinopharm BIBP COVID-19 vaccine § Variants, Sputnik V COVID-19 vaccine § Effectiveness, CoronaVac § Variants, Covaxin § Efficacy, ZF2001 § Efficacy, and Abdala (vaccine) § Efficacy
Summary of vaccine protection against Delta
(WHO's update, 24 August 2021[63])
Disease or infection Severe: protection retained
Symptomatic: possibly reduced protection
Severe disease  : AstraZeneca-Vaxzevria(1), Moderna(1), Pfizer-BioNTech(2)
Symptomatic disease   to  : Pfizer-BioNTech(3)
 : Covaxin(1)
  : AstraZeneca-Vaxzevria(2)
Infection  : AstraZeneca-Vaxzevria(1), Pfizer-BioNTech(1)
Symbols indicate the magnitude of vaccine effectiveness (VE) reduction. Note that VE reduction doesn't mean loss of protection, because original high protection rate (such as 95%) with some reduction (such as 10%) would still retain protection (such as 85%). Enclosed in parentheses is the number of studies supporting the indication. Studies vary in population, outcome definitions, study design, etc., which may explain differences in VE estimates for a product in different studies. Also, the reductions represent VE estimates and do not represent uncertainties around the estimates which may vary substantially across studies. The VE reductions should be interpreted with these limitations.

 : VE reduces <10%, or VE >90% without comparator
 : VE reduces between 10 and <20%

  : VE reduces between 20 and <30%
Effects on neutralization (fully vaccinated)[64]
  to  : Anhui-ZIFIVAX(2), Covaxin(3)
 : Janssen(3), Moderna(3), Covishield(2)
  to   : AstraZeneca-Vaxzevria(4), Pfizer-BioNTech(8)
  :Moderna & Pfizer-BioNTech(1)*
  to    : Coronavac(2)
Symbols indicate the magnitude of neutralization reduction with full vaccination. Enclosed in parentheses is the number of studies supporting the indication.

 : Neutralization reduces <2-fold
 : Neutralization reduces 2 to <5-fold
  : Neutralization reduces 5 to <10-fold
   : Neutralization reduces ≥ 10-fold
* Moderna & Pfizer-BioNTech were evaluated together.

WHO has not issued preventative measures against Delta specifically; non-pharmaceutical measures recommended to prevent wild type COVID-19 should still be effective. These would include washing hands, wearing a mask, maintaining distance from others, avoiding touching the mouth, nose or eyes, avoiding crowded indoor spaces with poor ventilation especially where people are talking, going to get tested if one develops symptoms and isolating if one becomes sick.[65] Public Health authorities should continue to find infected individuals using testing, trace their contacts, and isolate those who have tested positive or been exposed.[66] Event organizers should assess the potential risks of any mass gathering and develop a plan to mitigate these risks.[67] See also Non-pharmaceutical intervention (epidemiology).

The Indian Council of Medical Research (ICMR) found that convalescent sera of the COVID-19 cases and recipients of Bharat Biotech's BBV152 (Covaxin) were able to neutralise VUI B.1.617 although with a lower efficacy.[68]

Anurag Agrawal, the director of the Institute of Genomics and Integrative Biology (IGIB), said the study on the effectiveness of the available vaccines on lineage B.1.617 suggests that post-vaccination, the infections are milder.[69]

Anthony Fauci, the Chief Medical Advisor to the President of the United States, has also expressed his confidence regarding the preliminary results. In an interview on 28 April, he said:

This is something where we're still gaining data daily. But the most recent data was looking at convalescent sera of COVID-19 cases and people who received the vaccine used in India, the Covaxin. It was found to neutralise the 617 variants.[70]

Another study by the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad found Covishield (Oxford–AstraZeneca) vaccinated sera offers protection against lineage B.1.617.[71]

A study conducted by Public Health England (PHE), found that compared to those who were unvaccinated those who were vaccinated with either the Pfizer-BioNTech or AstraZeneca-Oxford had 33% less instances of symptomatic disease caused by the variant after the first dose. Among those who were two weeks after the receiving their second dose of the Pfizer-BioNTech vaccine 88% less subjects had symptomatic disease from the Delta variant versus those that were unvaccinated. Among those who were two weeks after the receiving their second dose of the AstraZeneca-Oxford vaccine 60% less subjects had symptomatic disease from the Delta variant versus those that were unvaccinated.[72][73]

A study by a group of researchers from the Francis Crick Institute, published in The Lancet, shows that humans fully vaccinated with the Pfizer-BioNTech vaccine are likely to have more than five times lower levels of neutralizing antibodies against the Delta variant compared to the original COVID-19 strain.[74][75]

In June 2021, PHE announced it had conducted a study which found that after two shots, the Pfizer-BioNTech vaccine and the AstraZeneca vaccine are respectively 96% and 92% effective at preventing hospitalisation from the Delta variant.[76][77]

On July 3, researchers from the universities of Toronto and Ottawa in Ontario, Canada, released a preprint study suggesting that the Moderna vaccine may be effective against death or hospitalization from the Delta variant.[78][unreliable medical source?]

In a study of the University of Sri Jayewardenepura in July 2021 found the Sinopharm BIBP vaccine caused seroconversion in 95% of individuals studied that had received both doses of the vaccine. The rate was higher in 20-39 age group (98.9%) but slightly lower in the over 60 age group (93.3%). Neutralising antibodies were present among 81.25% of the vaccinated individuals studied.[79][80]

On 29 June 2021, the director of the Gamaleya Institute, Denis Logunov, said that Sputnik V is about 90% effective against the Delta variant.[81]

On July 21, researchers from PHE published a study finding that the Pfizer vaccine was 93.7% effective against symptomatic disease from Delta after 2 doses, while the Astrazeneca vaccine was 67% effective.[82]

On August 2, several experts expressed concern that achieving herd immunity may not currently be possible because the Delta variant is transmitted among those immunized with current vaccines.[83]

On August 10, a study showed that the full vaccination coverage rate is correlated inversely to the SARS-CoV-2 delta variant mutation frequency in 16 countries (R-squared=0.878). Data strongly indicates that full vaccination against COVID-19 may slow down virus evolution.[84]

Treatment

See also: Treatment and management of COVID-19

In vitro experiments suggest that bamlanivimab may not be effective against Delta on its own.[85] At high enough concentrations, casirivimab, etesevimab and imdevimab appear to still be effective. A preprint study suggests that sotrovimab may also be effective against Delta.[86] Doctors in Singapore have been using supplemental oxygen, remdesivir and corticosteroids on more Delta patients than they did on previous variants.[87]

Epidemiology

Summary of impacts for Delta*
(WHO's update, 24 August 2021[63])
Transmissibility Increased transmissibility and secondary attack rate, similar transmissibility between vaccinated and unvaccinated individuals.
Virulence Increased risk of hospitalization
Reinfection Decreased neutralizing activity
Diagnostics No impacts yet reported
* Generalized finding compared to other strains, based on evidence including non-peer-reviewed publications.

Transmissibility

UK scientists have said that the Delta variant is between 40% and 60% more transmissible than the previously dominant Alpha variant, which was first identified in the UK (as the Kent variant).[88] Given that Alpha is already 150% as transmissible as the original SARS-CoV-2 strain that emerged in late 2019 in Wuhan,[88] and if Delta is 150% as transmissible as Alpha, then Delta may be 225% as transmissible as the original strain.[89] BBC reported that   – basic reproduction number, or the expected number of cases directly generated by one case in a population where all individuals are susceptible to infection – for the first detected SARS-CoV-2 virus is 2.4–2.6, whereas Alpha's reproduction number is 4–5 and Delta's is 5–9.[90][91] These basic reproduction numbers can be compared to MERS (0.29-0.80[92]), seasonal influenza (1.2–1.4[93]), Ebola (1.4–1.8[94]), common cold (2–3[95]), SARS (2–4[96]), smallpox (3.5–6[97]), and chickenpox (10–12[98]). Due to Delta's high transmissibility even those that are vaccinated are vulnerable,[99] albeit to a lesser extent.[73]

A study[100] published online (not peer-reviewed) by Guangdong Provincial Center for Disease Control and Prevention may partly explain the increased transmissibility: people with infection caused by Delta had 1,000 times more copies of the virus in the respiratory tracts than those with infection caused by variants first identified in the beginning of the pandemic; and it took on average 4 days for people infected with Delta for the virus to be detectable compared to 6 days with initially identified variants.[101][102]

Surveillance data from the U.S., Germany and the Netherlands indicates the Delta variant is growing by about a factor of 4 every two weeks with respect to the Alpha variant.[103][104][105]

In India, the United Kingdom,[106] Portugal,[107] Russia,[108] Mexico, Australia, Indonesia,[109] South Africa, Germany,[110] Luxembourg,[111] the United States,[112] the Netherlands,[113] Denmark,[114] France[115] and probably many other countries, the Delta variant had become the dominant strain by July 2021. Depending on country, there is typically a lag from a few days to several weeks between cases and variant reporting. As of July 20, this variant had spread to 124 countries,[64] and WHO had indicated that it was becoming the dominant strain, if not one already.[116]

In the Netherlands, the virus was still able to propagate significantly in the population with over 93.4% of blood donors being tested positive for SARS-CoV-2 antibodies after week 28, 2021. Many people there are not fully vaccinated, so those antibodies would have been developed from exposure to the wild virus or from a vaccine.[117][118] Similar high seroimmunity levels occur in the United Kingdom in blood donors and general surveillance.[119][120][121]

A preprint found that the viral load in the first positive test of infections with the variant was on average ~1000 times higher than with compared infections during 2020.[122][123] Preliminary data from a study with 100,000 volunteers in the UK from May to July 2021, when Delta was spreading rapidly, indicates that vaccinated people who test positive for COVID-19, including asymptomatic cases, have a lower viral load in average. Data from the US, UK, and Singapore indicate that vaccinated people infected by Delta may have viral loads as high as unvaccinated infected people, but might remain infectious for a shorter period.[124]

Infection age groups

Surveillance data from the Indian government's Integrated Disease Surveillance Programme (IDSP) shows that around 32% of patients, both hospitalised and outside hospitals, were aged below 30 in the second wave compared to 31% during the first wave, among people aged 30–40 the infection rate stayed at 21%. Hospitalisation in the 20–39 bracket increased to 25.5% from 23.7% while the 0–19 range increased to 5.8% from 4.2%. The data also showed a higher proportion of asymptomatic patients were admitted during the second wave, with more complaints of breathlessness.[125]

Virulence

See also: Virulence

A few early studies suggest the Delta variant causes more severe illness than other strains.[126] On 7 June 2021, researchers at the National Centre for Infectious Diseases in Singapore posted a paper suggesting that patients testing positive for Delta are more likely to develop pneumonia and/or require oxygen than patients with wild type or Alpha.[127] On June 11, Public Health England released a report finding that there was "significantly increased risk of hospitalization" from Delta as compared with Alpha;[128] the risk was approximately twice as high for those infected with the Delta variant.[129] On June 14, researchers from Public Health Scotland found that the risk of hospitalization from Delta was roughly double that of from Alpha.[130] On July 7, a preprint study from epidemiologists at the University of Toronto found that Delta had a 120% greater – or more than twice as large – risk of hospitalization, 287% greater risk of ICU admission and 137% greater risk of death compared to non-variant of concern strains of SARS-COV-2.[131] However, on July 9, Public Health England reported that the Delta variant in England had a case fatality rate (CFR) of 0.2%, while the Alpha variant's case fatality rate was 1.9%, although the report warns that "case fatality rates are not comparable across variants as they have peaked at different points in the pandemic, and so vary in background hospital pressure, vaccination availability and rates and case profiles, treatment options, and impact of reporting delay, among other factors."[132] James McCreadie, a spokesperson for Public Health England, clarified "It is too early to assess the case fatality ratio compared to other variants."[133]

A Canadian study released on 5 October 2021 revealed that the Delta variant caused a 108 percent rise in hospitalization, 235 percent increase in ICU admission, and a 133 percent surge in death compared to other variants. is more serious and resulted in an increased risk of death compared to previous variants, odds that are significantly decreased with immunization.[134][135]

Statistics

The chance of detecting a Delta case varies significantly, especially depending on a country's sequencing rate (less than 0.05% of all COVID-19 cases have been sequenced in the lowest-sequencing countries to around 50 percent in the highest).[136][137]

By 22 June 2021,[needs update] more than 4,500 sequences of the variant had been detected in about 78 countries.[138][139][140] Reported numbers of sequences in countries with detections are:

Cases by country
Country/Area Confirmed cases (PANGOLIN)[141]
as of 19 December 		Confirmed cases (GISAID)[138]
as of 23 November 		Cases (other sources)
as of 19 January 2022 		First detection Last detection
  United Kingdom 985,491 826,465 1,625,557[142] 22 February 2021
  United States 1,099,811 947,472 99.4% of cases[143] 23 February 2021
  Canada 78,412 62,008 196,866[144] 15 March 2021
  Germany 150,416 117,513 1 March 2021
  Denmark 138,336 89,706 8 March 2021
  Japan 86,383 70,973 86,037[145] [146] 28 March 2021
  France 75,224 70,822 21 February 2021
  Turkey 54,134 50,578 5[147] 28 April 2021
  Fiji 495 507 47,639 [148][149][150] 19 April 2021
  India 45,638 45,055 5 October 2020
   Switzerland 48,304 38,003 29 March 2021
  Sweden 46,018 37,773 26 March 2021
  Belgium 37,334 31,611 25 March 2021
  Italy 33,642 29,282 2 April 2021
  Spain 30,618 28,257 22 April 2021
  The Netherlands 33,128 27,870 6 April 2021
  Australia 23,696 22,715 25,750[151] 16 March 2021
  Ireland 22,425 21,061 26 February 2021
  Brazil 27,733 17,987 1051 [152][153] 20 May 2021[154][155][156][157][158]
  Mexico 20,230 17,710 5 April 2021
  Slovenia 16,334 13,439 20 April 2021
  Israel 15,787 12,259 41[159][160][161] 16 April 2021
  Norway 15,716 12,130 1[162] 15 April 2021
  Portugal 12,984 11,983 5 April 2021
  South Africa 2,582 10,619 4[163] 30 April 2021
  Poland 16,484 10,320 16[164] 26 April 2021
  Lithuania 899 9,070 1[165] 17 June 2021
  Finland 1,570 8,733 2,876[166][167][168][169] 18 March 2021
  Czech Republic 11,225 8,487 24 April 2021
  Singapore 2,727 7,510 26 February 2021
  Slovakia 353 7,146 15 June 2021
  Philippines 870 3,220 8,612[170][171] 11 May 2021
  South Korea 706 6,497 26 March 2021
  Croatia 479 6,165 11 June 2021
  Chile 64 5,858 13 June 2021
  Luxembourg 1,153 5,515 15 April 2021
  Indonesia 1,623 4,980 3 April 2021
  Romania 294 4,655 26 April 2021
  Bulgaria 231 4,614 5 April 2021
  Russia 1,468 4,295 16[172] 21 April 2021
  Thailand 236 4,293 2[173] 24 April 2021
  Iceland - 3,767 30 August 2021
  Malaysia 146 3,624 10 April 2021
  Austria 1,578 3,622 17 April 2021
  New Zealand 92 2,844 107[174][175] 9 March 2021
  Estonia - 2,740 21 July 2021
  Greece 17 2,642 23 March 2021
  Peru 6 2,580 10 June 2021
  Bahrain 117 2,013 5 April 2021
  Nigeria 36 1,795 1[176] 7 August 2021
  Kenya 256 1,700 5[176][177] 17 July 2021
  Aruba 90 1,592 16 April 2021
  Vietnam 54 1,414 12[178][179] 18 April 2021
  Puerto Rico 1,355 1,360 9 September 2021
  Qatar 121 1,343 19 April 2021
  Bangladesh 283 1,273 9[180][181] 28 April 2021
  Sint Maarten 1,225 1,231 19 March 2021
  Ecuador 955 1,023 20 July 2021
  Sri Lanka 117 984 1[182] 30 April 2021
  Colombia - 974 3 July 2021
  Botswana 196 912 2[183] 28 April 2021
  Gibraltar 835 848 5 September 2021
  Kosovo 829 834 2 May 2021
  Reunion 54 754 4 May 2021
  Cambodia 171 733 5 April 2021
  Papua New Guinea 710 717 10 August 2021
  Costa Rica 35 689 7 July 2021
  Pakistan 49 676 16 May 2021
  China 520 536 24 April 2021
  Maldives 6 525 31 July 2021
  Ghana 101 522 20 April 2021
  Curacao - 467 23 April 2021
  Bonaire - 458 13 July 2021
  Bosnia and Herzegovina 31 430 26 July 2021
  Ethiopia - 424 16 August 2021
  Seychelles - 407 30 September 2021
  Argentina 4 385 2[184] 24 April 2021
  Martinique 8 365 10 August 2021
  Guadeloupe - 362 10 March 2021
  Jordan 5 360 21 April 2021
  Uganda 134 340 1[185] 26 March 2021
  Zambia 82 326 29 May 2021
  Gambia 42 316 12 July 2021
  Mozambique - 314 16 July 2021
  Guatemala 4 302 29 July 2021
  Rwanda 91 283 9 July 2021
  Cameroon - 282 28 September 2021
  Georgia (country) 19 272 15 May 2021
  French Guiana 53 264 22 July 2021
  U.S. Virgin Islands - 247 18 August 2021
    Nepal 100 238 9[186] 28 April 2021
  DR Congo 19 228 5[176] 3 May 2021
  Malawi 5 213 30 April 2021
  Kuwait 108 191 5 June 2021
  Montenegro - 178 8 August 2021
  Ukraine 13 170 24 June 2021
  Kazakhstan - 167 19 August 2021
  Oman 8 159 17 May 2021
  Angola 6 159 14 January 2021
  Hong Kong 153 145 22 April 2021
  Suriname - 150 3 August 2021
  Morocco 3 138 2[187] 3 May 2021
  Togo - 130 31 July 2021
  Trinidad and Tobago - 114 3 August 2021
  Namibia - 110 June 2021
  Paraguay 4 100 8 July 2021
  Belize - 98 30 June 2021
  Egypt - 98 15 July 2021
  Zimbabwe - 96 26 July 2021
  Liechtenstein - 95 15 July 2021
  Senegal 13 93 6 May 2021
  Republic of Congo - 87 15 July 2021
  Västra Götaland - 86 19 July 2021
  Eswatini - 81 26 July 2021
  Lebanon - 80 3 July 2021
  Latvia 22 73 27 May 2021
  Monaco 34 70 15 May 2021
  Mauritius 15 67 8 May 2021
  Malta 42 63 23 June 2021
  Guinea-Bissau - 62 3 November 2021
  Burundi 3 57 31 May 2021
  Antigua and Barbuda - 57 6 August 2021
  Liberia - 56 10 July 2021
  Armenia - 50 5 August 2021
  Uzbekistan 30 47 (number unreported)[188] 25 June 2021
  Benin - 47 23 July 2021
  North Macedonia 6 38 11 July 2021
  The Bahamas - 38 8 August 2021
  Cayman Islands - 37 30 July 2021
  Myanmar 12 33 1 June 2021
  Serbia 5 33 6 July 2021
  Timor-Leste - 33 12[189] 8 August 2021
  South Sudan - 29 7 June 2021
  United Arab Emirates - 28 23 June 2021
  Brunei - 28 17 August 2021
  Gabon - 27 2 August 2021
  Mayotte - 27 21 October 2021
  Algeria 17 25 6[190] 28 July 2021
  Andorra - 25 17 July 2021
  Barbados 3 23 24 May 2021
  Sierra Leone - 22 8 September 2021
  Iran 11 21 3[191] 11 May 2021
  Burkina Faso - 21 21 April 2021
  Crimea - 21 1 July 2021
  Afghanistan - 20 24 May 2021
  Northern Mariana Islands 2 19 7 July 2021
  Central African Republic - 17 14 August 2021
  Taiwan 10 15 14 June 2021
  Guam - 14 26 April 2021
  Dominican Republic - 14 3 May 2021
  Hungary - - 14[192] 22 July 2021
  Equatorial Guinea - 14 30 August 2021
  Iraq 2 13 27 April 2021
  Moldova 11 11 6 July 2021
  Albania 11 11 13 July 2021
  Comoros 11 11 26 October 2021
  Jamaica 10 10 23 July 2021
  Anguilla 8 8 20 April 2021
  Saint Lucia 7 7 26 July 2021
  Montserrat 7 7 1 August 2021
  Saint Barthelemy 7 7 17 August 2021
  British Virgin Islands 5 5 27 July 2021
  Cyprus 1 1 4[193] 19 May 2021
  Turks and Caicos Islands 4 4 12 July 2021
  Azerbaijan 2 2 14 July 2021
  Honduras 2 2 31 July 2021
  El Salvador 2 2 2 August 2021
  Saint Vincent and the Grenadines 2 2 8 August 2021
  Mali 2 2 11 August 2021
  Saudi Arabia 2 2 9 September 2021
  Haiti 1 1 (number unreported)[188] 27 July 2021
  Panama 1 1 1[194] 29 April 2021
  Tunisia 1 1 21 May 2021
  Södermanland 1 1 7 July 2021
  Venezuela 1 1 7 July 2021
  Mongolia 1 1 23 September 2021
  Kyrgyzstan 1 1 (number unreported)[188] 16 May 2021[188]
 World (178 countries) Total: 3,119,592
(solely B.1.617.2)		 Total: 2,768,050
(B.1.617.2+AY.1+AY.2+AY.3)		 Total: 1,862,122


History

The first cases of the variant outside India were detected in late February 2021, including the United Kingdom on 22 February, the United States on 23 February and Singapore on 26 February.[195][40][138]

British scientists at Public Health England redesignated the B.1.617.2 variant on 7 May 2021 as "variant of concern" (VOC-21APR-02),[196] after they flagged evidence in May 2021 that it spreads more quickly than the original version of the virus.[21] Another reason was that they identified 48 clusters of B.1.617.2, some of which revealed a degree of community transmission.[197][198] With cases from the Delta variant having risen quickly, British scientists considered the Delta variant having overtaken the Alpha variant as the dominant variant of SARS-CoV-2 in the UK in early June 2021.[199] Researchers at Public Health England later found that over 90% of new cases in the UK in the early part of June 2021 were the Delta variant; they also cited evidence that the Delta variant was associated with an approximately 60% increased risk of household transmission compared to the Alpha variant.[200]

Canada's first confirmed case of the variant was identified in Quebec on 21 April 2021, and later the same day 39 cases of the variant were identified in British Columbia.[201] Alberta reported a single case of the variant on 22 April 2021.[202] Nova Scotia reported two Delta variant cases in June 2021.[203]

Fiji also confirmed its first case of the variant on 19 April 2021 in Lautoka, and has since then climbed up to 47,000 cases and counting.[204] The variant has been identified as a super-spreader and has led to the lockdowns of five cities (Lautoka, Nadi, Suva, Lami and Nausori), an area which accounts for almost two-thirds of the country's population.

On 29 April 2021, health officials from Finland's Ministry of Social Affairs and Health (STM) and the Finnish Institute for Health and Welfare (THL) reported that the variant had been detected in three samples dating back to March 2021.[166]

The Philippines confirmed its first two cases of the variant on 11 May 2021, despite the imposed travel ban of the country from the nations in the Indian subcontinent (except for Bhutan and Maldives). Both patients have no travel history from India for the past 14 days, but instead from Oman and UAE.[205]

North Macedonia confirmed its first case of the variant on 7 June 2021 after a person who was recovering from the virus in Iraq was transported to North Macedonia. In a laboratory test, the variant was detected in the person. On 22 June 2021, the country reported its second case of the Delta variant in a colleague of the first case who had also been in Iraq and who subsequently developed symptoms.[206]

The detection of B.1.617 was hampered in some countries by a lack of specialised kits for the variant and laboratories that can perform the genetic test.[207][208] For example, as of 18 May, Pakistan had not reported any cases, but authorities noted that 15% of COVID-19 samples in the country were of an "unknown variant"; they could not say if it was B.1.617 because they were unable to test for it. Other countries had reported travellers arriving from Pakistan that were infected with B.1.617.[207]

In June 2021, scientist Vinod Scaria of India's Institute of Genomics and Integrative Biology highlighted the existence of the B.1.617.2.1 variant, also known as AY.1 or Delta plus, which has an additional K417N mutation compared to the Delta variant.[53] B.1.617.2.1 was detected in Europe in March 2021, and has since been detected in Asia and America.[53]

On 23 June 2021, the European Centre for Disease Prevention and Control (ECDC) warned that the variant would represent 90% of all new cases in the European Union by the end of August.[209]

By 3 July 2021, Delta became dominant in the US.[210]

On 9 July 2021, Public Health England issued Technical Briefing 18 on SARS-CoV-2 variants, documenting 112 deaths among 45,136 UK cases of SARS-CoV-2 Delta variant with 28 days follow-up with a fatality rate of 0.2%.[211] Briefing 16 notes that "[M]ortality is a lagged indicator, which means that the number of cases who have completed 28 days of follow up is very low – therefore, it is too early to provide a formal assessment of the case fatality of Delta, stratified by age, compared to other variants."[212] Briefing 18 warns that "Case fatality is not comparable across variants as they have peaked at different points in the pandemic, and so vary in background hospital pressure, vaccination availability and rates and case profiles, treatment options, and impact of reporting delay, among other factors."[211] The most concerning issue is the logistic growth rate of 0.93/week relative to Alpha. This means that per week, the number of Delta samples/cases is growing by a factor of exp (0.93)=2.5 with respect to the Alpha variant. This results, under the same infection prevention measures, in a much greater case load over time until a large fraction of people have been infected by it.[213][214]

Government responses

After the rise in cases from the second wave, at least 20 countries imposed travel bans and restrictions on passengers from India in April and May. UK prime minister Boris Johnson cancelled his visit to India twice, while Japanese Prime Minister Yoshihide Suga postponed his April trip.[215][216][217]

In May 2021, residents of two tower blocks in Velbert, Germany, were quarantined after a woman in the building tested positive for the Delta variant.[218]

In May, Delhi Chief Minister Arvind Kejriwal said that a new coronavirus variant from Singapore was extremely dangerous for children and could result in a third wave in India.

From 16 May to 13 June 2021, as well as 22 July 2021 to 10 August 2021; Singapore entered lockdowns, known as "Phase 2 Heightened Alert", similar to 2020.

On 14 June, the British prime minister Boris Johnson announced that the proposed end of all restrictions on 21 June in the United Kingdom was delayed for up to four weeks and vaccination roll-out was accelerated following concerns over the Delta variant, which accounted for the vast majority (90%) of new infections.[219] UK scientists have said that the Delta variant is between 40% and 60% more transmissible than the previously dominant Alpha variant, which was first identified in the UK (as the Kent variant).[220]

On 23 June, the province of Ontario in Canada accelerated 2nd dose vaccine appointments for people living in Delta hot spots such as Toronto, Peel and Hamilton.[221]

On 25 June, Israel restored their mask mandate citing the threat of Delta.[222]

On 28 June, Sydney and Darwin went back into lockdown because of Delta outbreaks.[223] South Africa banned indoor and outdoor gatherings apart from funerals, imposed a curfew, and banned the sale of alcohol.[224]

On 3 July, the islands of Bali and Java in Indonesia went into emergency lockdown.[225]

On 8 July, Japanese Prime Minister Yoshihide Suga announced that Tokyo would once again enter a state of emergency, and that most spectators would be barred from attending the Olympics set to start there on 23 July.[226]

On 9 July, Seoul, South Korea ramped up restrictions urging people to wear masks outdoors, and limiting the size of gatherings.[227]

On 12 July, French President Emmanuel Macron announced that all health care workers will need to be vaccinated by 15 September and that France will start using health passports to enter bars, cafés, restaurants and shopping centres from August.[228]

Los Angeles announced it will require masks indoors starting 17 July 2021.[229]

The United Kingdom lifted most COVID-19 restrictions on 19 July, despite a surge in cases as the Delta variant became dominant. The government cited the protection and wide coverage of the COVID-19 vaccination programme, although health experts expressed concern at the move.[230][231]

On 23 July, Vietnam extended its lockdown of Ho Chi Minh City to 1 August, and announced lockdown restrictions would be put in place in Hanoi, affecting a third of the country's population. The Delta variant had brought upon the country's largest outbreak to date, after mostly successful containment measures throughout 2020.[232][233]

On 17 August, New Zealand went into an alert level 4 lockdown, following a positive case being reported in Auckland. More cases soon followed in the Coromandel Peninsula.[234] This was the first reported community transmission case in the country in 170 days (since February 2021).[235]

Extinction

In October 2021, Dr Jenny Harries, chief executive of the UK Health and Security Agency stated that previous circulating variants such as Alpha had 'disappeared' and replaced by the Delta variant.[236] In March 2022, the World Health Organization listed the Alpha, Beta and Gamma variants as previously circulating citing lack of any detected cases in the prior weeks and months, in part due to the dominance of the Delta variant and subsequent Omicron variant.[237] However within a few months the Delta variant was listed as a previously circulated variant with countries such as Australia going 12 weeks without any detections of Delta.[4]

See also

Notes

References

  1. ^ a b c d e Grover, Natalie (14 June 2021). "Delta variant Covid symptoms 'include headaches, sore throat and runny nose'". The Guardian. London. Retrieved 30 June 2021.
  2. ^ a b c Roberts, Michelle (14 June 2021). "Headache and runny nose linked to Delta variant". BBC News. London. Retrieved 2 July 2021.
  3. ^ "Tracking SARS-CoV-2 variants". www.who.int. Retrieved 17 August 2022.
  4. ^ a b "Variants of concern". CDGN. Retrieved 17 August 2022.
  5. ^ Lovelace, Berkeley Jr. (18 June 2021). "WHO says delta is becoming the dominant Covid variant globally". CNBC. Retrieved 1 November 2021.
  6. ^ a b Shang, Jian; Yushun, Wan; Lou, Chuming; Ye, Gang; Geng, Qibin; Auerbach, Ashley; Fang, Li (2020). "Cell entry mechanisms of SARS-CoV-2". Proceedings of the National Academy of Sciences. 117 (21): 11727–11734. Bibcode:2020PNAS..11711727S. doi:10.1073/pnas.2003138117. PMC 7260975. PMID 32376634.
  7. ^ "expert reaction to VUI-21APR-02/B.1.617.2 being classified by PHE as a variant of concern". sciencemediacentre.org. 7 May 2021. Retrieved 18 June 2021.
  8. ^ a b c Starr, Tyler N.; Greaney, Allison J.; Dingens, Adam S.; Bloom, Jesse D. (April 2021). "Complete map of SARS-CoV-2 RBD mutations that escape the monoclonal antibody LY-CoV555 and its cocktail with LY-CoV016". Cell Reports Medicine. 2 (4): 100255. doi:10.1016/j.xcrm.2021.100255. PMC 8020059. PMID 33842902.
  9. ^ a b c "SARS-CoV-2 variants of concern as of 24 May 2021". European Centre for Disease Prevention and Control. 30 April 2021. Retrieved 6 August 2021.
  10. ^ "Technical Briefing 20 SARS-CoV-2 variants of concern and variants under investigation in England" (PDF). 6 August 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  11. ^ "Technical Briefing 21 SARS-CoV-2 variants of concern and variants under investigation in England" (PDF). Public Health England. 20 August 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  12. ^ Sivan Gazit (25 August 2021). "Comparing SARS-CoV-2 natural immunity to vaccine-induced immunity: reinfections versus breakthrough infections". medRxiv 10.1101/2021.08.24.21262415v1. The study in Israel tracked 46035 unvaccinated recovered and 46035 vaccinated people of the same age distribution, to compare their infection occurrence in the follow-up period. 640 infections and 21 hospitalization in the vaccinated group and 108 infections and 4 hospitalizations in the recovered group were recorded.
  13. ^ "Past Covid-19 reduces risk of reinfection from Delta variant more than Pfizer vaccine". Bloomberg. 27 August 2021.
  14. ^ Burn-Murdoch, John; Mancini, Donato Paolo (9 July 2021). "How effective are coronavirus vaccines against the Delta variant?". www.ft.com. Retrieved 23 July 2021.
  15. ^ "Confirmed cases of COVID-19 variants identified in UK". www.gov.uk. 7 May 2021. from the original on 7 May 2021. Retrieved 7 May 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  16. ^ "Is The Variant From India The Most Contagious Coronavirus Mutant On The Planet?". NPR. 14 May 2021. cited "Eighty-ninth SAGE meeting on COVID-19, 13 May 2021 (Held via Video Teleconference)" (PDF). UK Government. 13 May 2021.
  17. ^ "06/15/2021: Lab Advisory: CDC Classifies SARS-CoV-2 Variant B.1.617.2 (Delta) a Variant of Concern". CDC. 15 June 2021.
  18. ^ WHO labels a Covid strain in India as a 'variant of concern' — here's what we know, CNBC, 11 May 2021.
  19. ^ "WHO says India Covid variant of 'global concern'", BBC News, 11 May 2021.
  20. ^ Narang, Deepanshu (22 April 2021). "COVID-19: The Second Wave May Not Be the Last – but Which One Will Be? – The Wire Science". Retrieved 20 May 2022.
  21. ^ a b Mishra, Swapnil; Mindermann, Sören; Sharma, Mrinank; Whittaker, Charles; Mellan, Thomas A.; Wilton, Thomas; Klapsa, Dimitra; Mate, Ryan; Fritzsche, Martin; Zambon, Maria; Ahuja, Janvi (1 September 2021). "Changing composition of SARS-CoV-2 lineages and rise of Delta variant in England". eClinicalMedicine. 39: 101064. doi:10.1016/j.eclinm.2021.101064. ISSN 2589-5370. PMC 8349999. PMID 34401689.
  22. ^ Callaway, Ewen (22 June 2021). "Delta coronavirus variant: scientists brace for impact". Nature. 595 (7865): 17–18. Bibcode:2021Natur.595...17C. doi:10.1038/d41586-021-01696-3. PMID 34158664. S2CID 235609029.
  23. ^ Rob Picheta (30 June 2021). "Britain thinks it can out-vaccinate the Delta variant. The world isn't so sure". CNN. Retrieved 2 July 2021.
  24. ^ a b "Health service buckling as third coronavirus wave fuelled by Delta variant sweeps across South Africa". the Guardian. 4 July 2021. Retrieved 7 July 2021.
  25. ^ Ellyatt, Holly (1 July 2021). "New Covid wave could be imminent as delta variant sweeps Europe, WHO says". CNBC. Retrieved 2 July 2021.
  26. ^ "Delta variant: Which Asian countries are seeing rising cases?". BBC News. 19 July 2021. Retrieved 23 July 2021.
  27. ^ "US in 'another pivotal moment' as Delta variant drives surge in Covid cases". the Guardian. 23 July 2021. Retrieved 23 July 2021.
  28. ^ "New Zealand suspends quarantine-free travel bubble with Australia". ITV News. 23 July 2021. Retrieved 23 July 2021.
  29. ^ a b "SARS-CoV-2 Variant Classifications and Definitions". CDC.gov. Centers for Disease Control and Prevention. 11 February 2020. Retrieved 15 June 2021.
  30. ^ "Genomic epidemiology of novel coronavirus - Global subsampling (Filtered to B.1.617)". nextstrain.org. Retrieved 5 May 2021.
  31. ^ "Covid Indian variant: Where is it, how does it spread and is it more infectious?". bbc.com. 7 June 2021.
  32. ^ "Weekly epidemiological update on COVID-19 - 27 April 2021" (PDF). World Health Organization. 27 April 2021. Retrieved 7 September 2021.
  33. ^ "Covid: WHO renames UK and other variants with Greek letters". BBC News. 31 May 2021. Retrieved 8 June 2021.
  34. ^ "SARS-CoV-2 Variant Classifications and Definitions". Centers for Disease Control and Prevention. 12 May 2021. Retrieved 16 May 2021.
  35. ^ Di Giacomo, Simone; Mercatelli, Daniele; Rakhimov, Amir; Giorgi, Federico M. (2021). "Preliminary report on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike mutation T478K". Journal of Medical Virology. 93 (9): 5638–5643. doi:10.1002/jmv.27062. PMC 8242375. PMID 33951211.
  36. ^ "Threat Assessment Brief: Emergence of SARS-CoV-2 B.1.617 variants in India and situation in the EU/EEA". European Centre for Disease Prevention and Control. 11 May 2021. Retrieved 17 May 2021.
  37. ^ Spike Variants: Delta variant, aka B.1.617.2 24 June 2021, covdb.stanford.edu, accessed 1 July 2021
  38. ^ "SARS-CoV-2 Variant Classifications and Definitions". cdc.gov. Centers for Disease Control and Prevention. 15 June 2021. Retrieved 18 June 2021.
  39. ^ "Dedicated 21A.S.478K Nextstrain build". covariants.org. 15 June 2021. Retrieved 19 June 2021.
  40. ^ a b "Expert reaction to cases of variant B.1.617 (the 'Indian variant') being investigated in the UK". Science Media Centre. Retrieved 20 April 2021.
  41. ^ "Delta (B.1.617.2) - GVN". 10 May 2021. Retrieved 27 November 2021.
  42. ^ "SARS-CoV-2 Spike protein (S1, T19R, G142D, del 156-157, R158G, L452R, T478K, D614G, P681R, His Tag) - Genscript". Retrieved 28 November 2021.
  43. ^ Greenwood, Michael (30 March 2021). "SARS-CoV-2 mutation T478K spreading at alarming speed in Mexico". Medical News. Retrieved 15 June 2021.
  44. ^ South, Andrew M.; Diz, Debra I.; Chappell, Mark C. (1 May 2020). "COVID-19, ACE2, and the cardiovascular consequences". American Journal of Physiology. Heart and Circulatory Physiology. 318 (5): H1084–H1090. doi:10.1152/ajpheart.00217.2020. PMC 7191628. PMID 32228252.
  45. ^ Zhang, Wenjuan; Davis, Brian D.; Chen, Stephanie S.; Sincuir Martinez, Jorge M.; Plummer, Jasmine T.; Vail, Eric (6 April 2021). "Emergence of a Novel SARS-CoV-2 Variant in Southern California". JAMA. 325 (13): 1324–1326. doi:10.1001/jama.2021.1612. PMC 7879386. PMID 33571356.
  46. ^ a b Haseltine, William. "An Indian SARS-CoV-2 Variant Lands In California. More Danger Ahead?". Forbes. Retrieved 20 April 2021.
  47. ^ Hoffmann, Markus; Hofmann-Winkler, Heike; Krüger, Nadine; Kempf, Amy; Nehlmeier, Inga; Graichen, Luise; Arora, Prerna; Sidarovich, Anzhalika; Moldenhauer, Anna-Sophie; Winkler, Martin S.; Schulz, Sebastian; Jäck, Hans-Martin; Stankov, Metodi V.; Behrens, Georg M.N.; Pöhlmann, Stefan (June 2021). "SARS-CoV-2 variant B.1.617 is resistant to Bamlanivimab and evades antibodies induced by infection and vaccination". Cell Reports. 36 (3): 109415. doi:10.1016/j.celrep.2021.109415. ISSN 2211-1247. PMC 8238662. PMID 34270919. Collectively, our study reveals that antibody evasion of B.1.617 may contribute to the rapid spread of this variant... ...The RBD of the B.1.617 S protein harbors two mutations associated with (L452R) or suspected (E484Q) of antibody evasion... ...Moreover, E484K present the B.1.351 and P.1 variants confers antibody resistance (Li et al., 2021) and one could speculate that exchange E484Q might have a similar effect.
  48. ^ "感染・伝播性の増加や抗原性の変化が懸念される 新型コロナウイルス（SARS-CoV-2）の新規変異株について （第13報）" [Infection: New variant of coronavirus (SARS-CoV-2): concerns as to increased infectivity / transmission and changes in antigenicity]. niid.go.jp (in Japanese). National Institute of Infectious Diseases (NIID). 28 August 2021. Retrieved 5 September 2021.
  49. ^ "New AY lineages and an update to AY.4-AY.12". pango.network. PANGO Network. 27 August 2021. Retrieved 5 September 2021.
  50. ^ SARS-CoV-2 variants of concern and variants under investigation in England, technical briefing 16 (PDF) (Briefing). Public Health England. 18 June 2021. GOV-8641. Retrieved 23 June 2021.
  51. ^ "CDPHE to update variant data to align with CDC". Colorado Department of Public Health and Environment. State of Colorado. 17 August 2021. Retrieved 25 October 2021. AY.1, AY.2, and AY.3 -- commonly referred to as delta plus
  52. ^ Cutler, S (18 June 2021). "'Nepal variant': what we've learned so far". The Conversation. Retrieved 6 August 2021.
  53. ^ a b c "Delta plus: New Covid variant identified, experts say no cause of concern for now". The Indian Express. Press Trust of India. 14 June 2021. Retrieved 23 June 2021.
  54. ^ Sample, Ian (3 June 2021). "Nepal Covid variant: does it exist and should we be concerned?". The Guardian. Retrieved 23 June 2021.
  55. ^ Tang, Julian W.; Oliver, T.R. (2021). "Introduction of the South African SARS-CoV-2 variant 501Y.V2 into the UK". The Journal of Infection. 82 (4): e8–e10. doi:10.1016/j.jinf.2021.01.007. ISSN 0163-4453. PMC 7813514. PMID 33472093.
  56. ^ "AY.3 Lineage Report". outbreak.info. Updates constantly.
  57. ^ "SARS-CoV-2 variants of concern and variants under investigation in England Technical briefing 25" (PDF). UK Health Security Agency. 15 October 2021. Retrieved 26 October 2021.
  58. ^ Davis, Nicola (19 October 2021). "Offshoot of Covid Delta variant on the rise in England". The Guardian.
  59. ^ "SARS-CoV-2 variants of concern and variants under investigation in England: technical briefing 29" (PDF). GOV.UK. Retrieved 30 October 2021.
  60. ^ Roberts, Michelle (22 October 2021). "Delta 'Plus' Covid variant may be more transmissible". BBC News.
  61. ^ name. "Den nye Delta-undervariant AY.4.2 viser ikke tegn på nedsat vaccineeffektivitet". www.ssi.dk (in Danish). Retrieved 14 November 2021.
  62. ^ "outbreak.info". outbreak.info. Retrieved 14 November 2021.
  63. ^ a b "Weekly epidemiological update on COVID-19 – 24 August 2021". World Health Organization. 24 August 2021.
  64. ^ a b "Weekly epidemiological update on COVID-19 - 20 July 2021". World Health Organization. 20 July 2021.
  65. ^ "Advice for Public". WHO. Retrieved 14 July 2021.
  66. ^ "Health Workers and Administrators". WHO. Retrieved 14 July 2021.
  67. ^ "Key planning recommendations for mass gatherings in the context of the current COVID-19 outbreak". WHO. Retrieved 14 July 2021.
  68. ^ Yadav, PD; Sapkal, GN; Abraham, P; Ella, R; Deshpande, G; Patil, DY; et al. (7 May 2021). "Neutralization of variant under investigation B.1.617 with sera of BBV152 vaccinees". Clinical Infectious Diseases. 74 (2): 366–368. doi:10.1093/cid/ciab411. PMID 33961693.
  69. ^ "Covishield Covaxin effective against 'Indian strain' of coronavirus study suggests". The Week. Retrieved 27 April 2021.
  70. ^ "Covaxin found to neutralise 617 variant of COVID-19, says Dr. Fauci". The Hindu. 28 April 2021.
  71. ^ "Covishield, Covaxin effective against 'Indian strain' of coronavirus, study suggests - ET HealthWorld". ETHealthworld.com. The Economic Times. 28 April 2021.
  72. ^ Ellyatt, Holly (24 May 2021). "Two doses of Covid vaccines provide effective protection against variant found in India: Study". CNBC.
  73. ^ a b Bernal, Jamie Lopez; Andrews, Nick; Gower, Charlotte; Gallagher, Eileen; Simmons, Ruth; Thelwall, Simon; et al. (24 May 2021). "Effectiveness of COVID-19 vaccines against the B.1.617.2 variant". medRxiv 10.1101/2021.05.22.21257658v1.
  74. ^ Wall, Emma C; Wu, Mary; Harvey, Ruth; Kelly, Gavin; Warchal, Scott; Sawyer, Chelsea; et al. (June 2021). "Neutralising antibody activity against SARS-CoV-2 VOCs B.1.617.2 and B.1.351 by BNT162b2 vaccination". The Lancet. 397 (10292): 2331–2333. doi:10.1016/s0140-6736(21)01290-3. ISSN 0140-6736. PMC 8175044. PMID 34090624.
  75. ^ "COVID-19 vaccine: Pfizer jabs not the best for Delta variant, says Lancet study". The New Indian Express. 5 June 2021.
  76. ^ "Vaccines highly effective against hospitalisation from Delta variant". www.gov.uk. Public Health England. 14 June 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  77. ^ "UK study finds vaccines offer high protection against hospitalisation from Delta variant". Reuters. 14 June 2021. Retrieved 15 June 2021.
  78. ^ Nasreen S, He S, Chung H, Brown KA, Gubbay JB, Buchan SA, et al. (3 July 2021). "Effectiveness of COVID-19 vaccines against variants of concern, Canada". medRxiv 10.1101/2021.06.28.21259420v1.
  79. ^ "Over 95% individuals developed antibodies against the Sinopharm vaccine - USJ Researchers". USJ - University of Sri Jayewardenepura, Sri Lanka. 20 July 2021. Retrieved 20 July 2021.
  80. ^ Jeewandara, Chandima; Aberathna, Inoka Sepali; Pushpakumara, Pradeep Dharshana; Kamaladasa, Achala; Guruge, Dinuka; Jayathilaka, Deshni; Gunesekara, Banuri; Tanussiya, Shyrar; Kuruppu, Heshan; Ranasinghe, Thushali; Dayarathne, Shashika (19 July 2021). "Antibody and T cell responses to Sinopharm/BBIBP-CorV in naive and previously infected individuals in Sri Lanka". medRxiv 10.1101/2021.07.15.21260621v1.
  81. ^ "Russia's Sputnik V shot around 90% effective against Delta variant, developers say". Reuters. 29 June 2021. Retrieved 11 August 2021.
  82. ^ Lopez Bernal, Jamie; Andrews, Nick; Gower, Charlotte; Gallagher, Eileen; Simmons, Ruth; Thelwall, Simon; Stowe, Julia; Tessier, Elise; Groves, Natalie; Dabrera, Gavin; Myers, Richard; Campbell, Colin N.J.; Amirthalingam, Gayatri; Edmunds, Matt; Zambon, Maria; Brown, Kevin E.; Hopkins, Susan; Chand, Meera; Ramsay, Mary (2021). "Effectiveness of Covid-19 Vaccines against the B.1.617.2 (Delta) Variant". New England Journal of Medicine. 385 (7): 585–594. doi:10.1056/NEJMoa2108891. ISSN 0028-4793. PMC 8314739. PMID 34289274.
  83. ^ Dyer, Owen (2 August 2021). "Covid-19: Delta infections threaten herd immunity vaccine strategy". BMJ. 374: n1933. doi:10.1136/bmj.n1933. ISSN 1756-1833. PMID 34340962. S2CID 236778544.
  84. ^ Yeh TY, Contreras, GP (10 August 2021). "Full vaccination suppresses SARS-CoV-2 delta variant mutation frequency". medRxiv 10.1101/2021.08.08.21261768v2.
  85. ^ Delphine Planas (8 July 2021). "Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization". Nature. 596 (7871): 276–280. Bibcode:2021Natur.596..276P. doi:10.1038/s41586-021-03777-9. PMID 34237773. S2CID 235775860.
  86. ^ Andrea Cathcart (26 July 2021). "The dual function monoclonal antibodies VIR-7831 and VIR-7832 demonstrate potent in vitro and in vivo activity against SARS-CoV-2". bioRxiv. doi:10.1101/2021.03.09.434607. S2CID 232223983. Retrieved 30 July 2021.
  87. ^ Sean Wei Xiang Ong (7 June 2021). "Clinical and Virological Features of SARS-CoV-2 Variants of Concern: A Retrospective Cohort Study Comparing B.1.1.7 (Alpha), B.1.315 (Beta), and B.1.617.2 (Delta)". SSRN 3861566.
  88. ^ a b "How Dangerous Is the Delta Variant, and Will It Cause a COVID Surge in the U.S.?". Scientific American. 29 June 2021. cited "SPI-M-O: Consensus Statement on COVID-19" (PDF). UK Government. 2 June 2021. (PDF) from the original on 20 July 2021.
  89. ^ Aubrey, Allison; Simmons-Duffin, Selena (17 July 2021). "With The Delta Variant Spreading Fast, Is It Time To Mask Up Again?". NPR. from the original on 2 August 2021. cited Doucleff, Michaeleen (14 May 2021). "Is The Variant From India The Most Contagious Coronavirus Mutant On The Planet?". NPR. from the original on 2 August 2021.
  90. ^ Kollmeyer, Barbara (30 July 2020). "'As transmissible as chickenpox.' Here's the CDC report on the delta variant that led to new mask policy". MarketWatch. from the original on 2 August 2021. Retrieved 3 August 2021.
  91. ^ Gallagher, James (12 June 2021). "Covid: Is there a limit to how much worse variants can get?". BBC News. from the original on 3 August 2021.
  92. ^ Kucharski AJ, Althaus CL (June 2015). "The role of superspreading in Middle East respiratory syndrome coronavirus (MERS-CoV) transmission". Euro Surveillance. 20 (25): 14–8. doi:10.2807/1560-7917.ES2015.20.25.21167. PMID 26132768.
  93. ^ Chowell G, Miller MA, Viboud C (June 2008). "Seasonal influenza in the United States, France, and Australia: transmission and prospects for control". Epidemiology and Infection. Cambridge University Press. 136 (6): 852–64. doi:10.1017/S0950268807009144. PMC 2680121. PMID 17634159. The reproduction number across influenza seasons and countries lied in the range 0.9–2.0 with an overall mean of 1.3, and 95% confidence interval (CI) 1.2–1.4.
  94. ^ Wong ZS, Bui CM, Chughtai AA, Macintyre CR (April 2017). "A systematic review of early modelling studies of Ebola virus disease in West Africa". Epidemiology and Infection. 145 (6): 1069–1094. doi:10.1017/S0950268817000164. PMC 9507849. PMID 28166851. The median of the R0 mean estimate for the ongoing epidemic (overall) is 1.78 (interquartile range: 1.44, 1.80)
  95. ^ Freeman C (6 November 2014). "Magic formula that will determine whether Ebola is beaten". The Telegraph. Telegraph.Co.Uk. Archived from the original on 11 January 2022. Retrieved 30 March 2020.
  96. ^ Consensus document on the epidemiology of severe acute respiratory syndrome (SARS). Department of Communicable Disease Surveillance and Response (Technical report). World Health Organization. p. 26. hdl:10665/70863. WHO/CDS/CSR/GAR/2003.11. A number of researchers have estimated the basic reproduction number by fitting models to the initial growth of epidemics in a number of countries. Their observations indicate that the SARS-CoV is less transmissible than initially thought with estimates of Ro in the range of 2–4.
  97. ^ Gani R, Leach S (December 2001). "Transmission potential of smallpox in contemporary populations". Nature. 414 (6865): 748–51. Bibcode:2001Natur.414..748G. doi:10.1038/414748a. PMID 11742399. S2CID 52799168. Retrieved 18 March 2020.
  98. ^ Ireland's Health Services. Health Care Worker Information (PDF). Retrieved 27 March 2020.
  99. ^ Brown, Catherine M. (2021). "Outbreak of SARS-CoV-2 Infections, Including COVID-19 Vaccine Breakthrough Infections, Associated with Large Public Gatherings — Barnstable County, Massachusetts, July 2021". MMWR. Morbidity and Mortality Weekly Report. 70 (31): 1059–1062. doi:10.15585/mmwr.mm7031e2. ISSN 0149-2195. PMC 8367314. PMID 34351882.
  100. ^ Lu, Jing (7 July 2021). "Viral infection and transmission in a large well-traced outbreak caused by the Delta SARS-CoV-2 variant". virological.org. from the original on 22 July 2021.
  101. ^ "Why The Delta Variant Is Hyper-Contagious: A New Study Sheds Light". NPR. 21 July 2021.
  102. ^ Haseltine, William A (13 July 2021). "The Delta Dilemma: Loosening Covid-19 Controls At A Time Of Increased Danger". Forbes.
  103. ^ "CDC covid variant tracker". 28 March 2020. Retrieved 13 July 2021.
  104. ^ "RIVM Covid variant tracker". Retrieved 13 July 2021.
  105. ^ "RKI - Coronavirus SARS-CoV-2 - Berichte zu Virusvarianten von SARS-CoV-2 in Deutschland". www.rki.de. Retrieved 19 June 2021.
  106. ^ Cave, Damien (2 July 2021). "Why the Delta Variant Could End Australia's Pursuit of 'Covid Zero'". The New York Times. Retrieved 9 July 2021.
  107. ^ Demony, Catarina (26 June 2021). "Delta variant 'spreading rapidly' from Lisbon to rest of Portugal". Reuters. Retrieved 28 June 2021.
  108. ^ . Deutsche Welle. 8 July 2021. Archived from the original on 9 July 2021. Retrieved 9 July 2021.
  109. ^ Lawler, Dave (8 July 2021). "Indonesia's surging death rate underscores danger of Delta variant". Axios. Retrieved 16 July 2021.
  110. ^ "Delta-Variante dominiert in Deutschland". www.aerzteblatt.de (in German). 8 July 2021. Retrieved 9 July 2021.
  111. ^ "14 to 20 June: Delta variant dominates cases in Luxembourg with 59.4 percent". today.rtl.lu. Retrieved 3 July 2021.
  112. ^ "From UK to Indonesia: How Delta variant is dominating global Covid surge". The Times of India. 8 July 2021. Retrieved 16 July 2021.
  113. ^ "Delta variant rapidly advancing in Netherlands; Possibly caused 50% of infections". NL Times. Retrieved 3 July 2021.
  114. ^ "Risikovurdering af B.1.617.2 - opdatering" (PDF). 2 July 2021.
  115. ^ "Delta variant to account for most new French COVID cases from this weekend - minister". Reuters. 9 July 2021. Retrieved 9 July 2021.
  116. ^ "WHO Director-General's opening remarks at the 8th meeting of the IHR Emergency Committee on COVID-19 - 14 July 2021". WHO. 14 July 2021. from the original on 15 July 2021. The Delta variant is now in more than 111 countries and we expect it to soon be the dominant COVID-19 strain circulating worldwide, if it isn't already.
  117. ^ "Corona-antistoffen bij 93% van donors". Sanquin Netherlands (in Dutch). Retrieved 29 July 2021.
  118. ^ "Antistoffen bij 95% van donors". Sanquin (in Dutch). Retrieved 30 October 2021.
  119. ^ "Most Blood Donations Contain COVID-19 Antibodies". www.precisionvaccinations.com. Retrieved 30 October 2021.
  120. ^ "Coronavirus (COVID-19) latest insights - Office for National Statistics". www.ons.gov.uk. Retrieved 30 October 2021.
  121. ^ "COVID-19 vaccine surveillance report Week 43" (PDF).
  122. ^ Reardon, Sara (21 July 2021). "How the Delta variant achieves its ultrafast spread". Nature. doi:10.1038/d41586-021-01986-w. Retrieved 13 August 2021.
  123. ^ Li, Baisheng; et al. (23 July 2021). "Viral infection and transmission in a large, well-traced outbreak caused by the SARS-CoV-2 Delta variant". medRxiv 10.1101/2021.07.07.21260122v2.
  124. ^ Subbaraman, Nidhi (12 August 2021). "How do vaccinated people spread Delta? What the science says". Nature. 596 (7872): 327–328. Bibcode:2021Natur.596..327S. doi:10.1038/d41586-021-02187-1. PMID 34385613. S2CID 236997139.
  125. ^ Dey, Sushmi. "Covid second wave in India: Percentage of young infected in second wave same, but more serious". The Times of India. Retrieved 27 April 2021.
  126. ^ Delta Variant: What We Know About the Science, by Centers for Disease Control and Prevention
  127. ^ Ong, Sean Wei Xiang; Chiew, Calvin J.; Ang, Li Wei; Mak, Tze-Minn; Cui, Lin; Toh, Matthias Paul HS; Lim, Yi Ding; Lee, Pei Hua; Lee, Tau Hong; Chia, Po Ying; Maurer-Stroh, Sebastian; Lin, Raymond Tzer Pin; Leo, Yee-Sin; Lee, Vernon J.; Lye, David Chien; Young, Barnaby E. (7 June 2021). "Clinical and Virological Features of SARS-CoV-2 Variants of Concern: A Retrospective Cohort Study Comparing B.1.1.7 (Alpha), B.1.315 (Beta), and B.1.617.2 (Delta)". SSRN 3861566.
  128. ^ Public Health England (11 June 2021). "SARS-CoV-2 variants of concern and variants under investigation in England Technical briefing 15" (PDF). gov.uk. p. 50. Retrieved 22 July 2021.
  129. ^ Twohig, Katherine A.; Nyberg, Tommy; Zaidi, Asad; Thelwall, Simon; Sinnathamby, Mary A.; Aliabadi, Shirin; Seaman, Shaun R.; Harris, Ross J.; Hope, Russell; Lopez-Bernal, Jamie; Gallagher, Eileen (27 August 2021). "Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with alpha (B.1.1.7) variants of concern: a cohort study". The Lancet Infectious Diseases. 22 (1): 35–42. doi:10.1016/S1473-3099(21)00475-8. ISSN 1473-3099. PMC 8397301. PMID 34461056.
  130. ^ Sheikh, Aziz; McMenamin, Jim; Taylor, Bob; Robertson, Chris (2021). "SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness". The Lancet. 397 (10293): 2461–2462. doi:10.1016/S0140-6736(21)01358-1. ISSN 0140-6736. PMC 8201647. PMID 34139198.
  131. ^ Fisman, David; Tuite, Ashleigh (12 July 2021). "Progressive Increase in Virulence of Novel SARS-CoV-2 Variants in Ontario, Canada". medRxiv 10.1101/2021.07.05.21260050v2.
  132. ^ "SARS-CoV-2 variants of concern and variants under investigation in England" (PDF). assets.publishing.service.gov.uk. Public Health England Technical Briefing 18. 9 July 2021. pp. 10–11, Table 3 and footnote 2 of that table. Retrieved 19 July 2021.  This article incorporates text published under the British Open Government Licence v3.0:
  133. ^ Kertscher, Tom (7 July 2021). "Data showing lower death rate for coronavirus delta variant doesn't mean it's less dangerous". Politifact. Retrieved 20 July 2021.
  134. ^ Fisman, David N.; Tuite, Ashleigh R. (4 October 2021). "Evaluation of the relative virulence of novel SARS-CoV-2 variants: a retrospective cohort study in Ontario, Canada". Canadian Medical Association Journal. 193 (42): –211248. doi:10.1503/cmaj.211248. ISSN 1488-2329. PMC 8562985. PMID 34610919.
  135. ^ "Canadian Study Reveals Delta Lethality Higher than Original COVID - October 6, 2021". Daily News Brief. 6 October 2021. Retrieved 6 October 2021.
  136. ^ Berger, Miriam (28 November 2021). "South Africa, which found the omicron variant first, leads Africa in coronavirus sequencing". Washington Post. Retrieved 2 December 2021.
  137. ^ . GISAID. 2 December 2021. Archived from the original on 2 December 2021. Retrieved 2 December 2021.
  138. ^ a b c "Tracking of Variants". gisaid.org. GISAID. 26 April 2021. Retrieved 23 November 2021.
  139. ^ "Weekly epidemiological update on COVID-19 - 11 May 2021". World Health Organization. 11 May 2021. Retrieved 27 July 2021.
  140. ^ "Weekly epidemiological update on COVID-19 - 22 June 2021". www.who.int. Retrieved 29 June 2021.
  141. ^ "PANGO lineages Lineage B.1.617.2". cov-lineages.org. Retrieved 19 December 2021.
  142. ^ "COVID-19 variants: genomically confirmed case numbers". Gov.uk. Retrieved 19 December 2021.
  143. ^ "Variant Proportions". Cdc.gov. 28 March 2020. Retrieved 30 July 2021.
  144. ^ "Tracking variants of the novel coronavirus in Canada". Ctvnews.ca. 4 February 2021. Retrieved 19 December 2021.
  145. ^ "Infectious Diseases Weekly Report". National Institute of Infectious Diseases. Retrieved 30 July 2021.
  146. ^ "都道府県別の懸念される変異株の国内事例数(ゲノム解析)について". Ministry of Health, Labour and Welfare. Retrieved 30 July 2021.
  147. ^ "Coronavirus live news, 16:54, 28 April 2021". The Guardian. 28 April 2021. Retrieved 28 April 2021.
  148. ^ The index case of the second wave was determined to be the Delta variant. There have been over 47,000 cases originating from the index case."Fiji Ministry of Health and Medical Services COVID-19 Cases". Retrieved 5 September 2021.
  149. ^ "Fiji COVID-19 update for 10 July 2021". Fiji Village News. 10 July 2021. Retrieved 10 July 2021.
  150. ^ "Fiji is racing against time to vaccinate its population while a COVID-19 outbreak explodes". ABC News. 10 July 2021. Retrieved 11 July 2021.
  151. ^ "Variants of Concern". Communicable Disease Genomes Network. Retrieved 5 December 2021.
  152. ^ SP identifica primeiro caso de variante do coronavírus em passageiro vindo da Índia 26/05/2021 g1.globo.com, accessed 26 May 2021
  153. ^ Covid-19: Maranhão registra primeiros casos da variante indiana 21 May 2021 pebmed.com.br, accessed 26 May 2021
  154. ^ Barbosa, Alex (24 May 2021). "Identificação da variante indiana do coronavírus coincide com aumento de internações no Maranhão". g1.globo.com (in Brazilian Portuguese). TV Mirante e G1 MA.
  155. ^ Coronavírus: Primeiro caso da variante indiana é confirmado no Paraná, diz Sesa (tr. "Coronavirus: First case of the Indian variant is confirmed in Paraná, says Sesa ") 02/06/2021 g1.globo.com, accessed 3 June 2021
  156. ^ Variante delta do coronavírus é identificada e tem transmissão comunitária em Goiânia g1.globo.com, accessed 23 June 2021
  157. ^ "Casos da variante Delta podem estar subnotificados no Brasil".
  158. ^ "Delta: Brasil supera mil casos confirmados da variante; crescimento foi de 84% em uma semana - Saúde".
  159. ^ Soni, Parul (30 April 2021). "Israel Is The Most Vaccinated Country, But The B.1.617 Is Threatening It Now". International Business Times. IBT Media.
  160. ^ "Israel logs Indian COVID-19 variant, sees some vaccine efficacy against it". Reuters. 20 April 2021. Retrieved 24 April 2021.
  161. ^ "זוהו 41 מקרים של הזן (הווריאנט) ההודי, מתוכם 24 חוזרים מחו"ל" [41 cases of the Indian variety have been identified, of which 24 are from abroad]. GOV.IL (in Hebrew). Retrieved 29 April 2021.
  162. ^ "Indisk virusvariant påvist i Norge" [Indian virus variant detected in Norway]. dagbladet.no. 16 April 2021. Retrieved 28 April 2021.
  163. ^ "Update On Covid-19 (08th May 2021) - SA Corona Virus Online Portal". SA Corona Virus Online Portal. Retrieved 10 May 2021.
  164. ^ "Minister zdrowia: mamy kolejne dwa ogniska związane z mutacją indyjską koronawirusa" [Health Minister: We have two more outbreaks related to the Indian mutation of the coronavirus]. tvn24.pl (in Polish). 4 May 2021. Retrieved 4 May 2021.
  165. ^ "Lithuania detects first case of coronavirus Delta variant from India". lrt.lt/en/news-in-english. 17 June 2021. Retrieved 17 June 2021.
  166. ^ a b "Indian Covid variant reaches Finland". YLE. Finland. 29 April 2021. Retrieved 13 May 2021.
  167. ^ "Intialaiseen muunnokseen on sairastunut Suomessa kymmenkunta henkeä – Uudenmaan koronaviruskanta on vaihtunut täysin alkuvuoden aikana" [About a dozen people in Finland have contracted the Indian variant - the coronavirus variants seen in Uusimaa have completely changed in the first part of the year]. yle.fi (in Finnish). 10 May 2021. Retrieved 17 May 2021.
  168. ^ "Virologist: Indian variant not major concern in Finland, though care should be taken". Yle. Finland. 27 May 2021. Retrieved 27 May 2021.
  169. ^ "Situation update on coronavirus - Coronavirus variants". Finnish Institute for Health and Welfare. 11 August 2021. Retrieved 11 August 2021. Delta-variant: 2,876
  170. ^ de Vera, Analou (9 December 2021). "DOH: No Omicron variant yet in PH". Manila Bulletin. Retrieved 10 December 2021.
  171. ^ "Philippines detects 492 new Omicron cases, total at 535". GMA News. 19 January 2022. Retrieved 24 January 2022.
  172. ^ "Russia records first cases of COVID variant found in India". The Economic Times. Retrieved 13 May 2021.
  173. ^ "Indian variant of Covid-19 confirmed in Thailand". Bangkok Post. 10 May 2021. Retrieved 11 May 2021.
  174. ^ Osborne, Samuel (23 August 2021). "COVID-19: New Zealand extends coronavirus lockdown amid Delta variant outbreak". Sky News. Retrieved 23 August 2021. New Zealand reported 35 new cases of COVID-19, bringing the number of current infections to 107.
  175. ^ Clark, Emily (22 August 2021). "New Zealand COVID-19 outbreak grows, strict lockdown extended". abc.net.au. Retrieved 23 August 2021. The strict level 4 lockdown across New Zealand has been extended as the country's Delta outbreak climbs to more than 100 cases.
  176. ^ a b c "Nigeria, Algeria report Indian variant of the coronavirus, WHO says without further details". africanews.com. 13 May 2021. Retrieved 14 May 2021.
  177. ^ "Covid Indian Variant Detected In Kenya". ndtv.com. 5 May 2021. Retrieved 7 May 2021.
  178. ^ "Vietnam detects 'double mutant' Indian variant of coronavirus for 1st time". tuoitrenews.vn. 2 May 2021. Retrieved 17 May 2021.
  179. ^ "Indian coronavirus variant found in COVID-19 cases linked to National Hospital for Tropical Diseases". vietnamnews.vn. 11 May 2021. Retrieved 17 May 2021.
  180. ^ "IEDCR: Indian Covid variant found in six Bangladeshis". Dhaka Tribune. 17 May 2021. Retrieved 18 May 2021.
  181. ^ "যশোরে আরো ৩জনের শরীরে করোনার ভারতীয় ভ্যারিয়েন্ট শনাক্ত" [Indian variant of coronavirus identified in 3 more people in Jessore District]. Youtube. Jamuna TV. 18 May 2021. Retrieved 18 May 2021.
  182. ^ "Covid-19 Indian variant spreads to neighbouring countries; detected in Sri Lanka, Bangladesh". Times of India. 8 May 2021. Retrieved 11 May 2021.
  183. ^ "Botswana confirms new COVID-19 variant". Weekend Post. 17 May 2021. Retrieved 18 May 2021.
  184. ^ "Cases of South African and Indian coronavirus strains detected in Argentina". MercoPress. 11 May 2021. Retrieved 11 May 2021.
  185. ^ "Raising fears of COVID surge, Uganda detects Indian variant, official says". Reuters. 30 April 2021. Retrieved 8 May 2021.
  186. ^ "Nepal reports more Covid-19 deaths and record daily new infections". Kathmandu Post. 11 May 2021. Retrieved 11 May 2021.
  187. ^ Yabiladi.com. "Morocco : Two cases of the Indian variant of Covid-19 confirmed in Casablanca". en.yabiladi.com (in French). Retrieved 3 May 2021.
  188. ^ a b c d "Weekly epidemiological update on COVID-19 - 18 May 2021". World Health Organization. 18 May 2021. Retrieved 19 May 2021.
  189. ^ Lamb, Kate (10 August 2021). "East Timor detects first domestic transmission of COVID-19 Delta variant". Reuters. Retrieved 13 August 2021.|
  190. ^ "Algeria finds first cases of Indian coronavirus variant". Reuters. 4 May 2021. Retrieved 14 May 2021.
  191. ^ "Iran reports three cases of Indian coronavirus variant". Al Arabiya. 5 May 2021. Retrieved 14 May 2021.
  192. ^ "Coronavirus: New Variants Confirmed in 15 New Cases". Hungary Today. 22 July 2021. Retrieved 28 August 2021. Tests by the National Public Health Centre (NNK) showed the presence of the Delta variant of the coronavirus in 14 new cases and the gamma variant in one new case, the prime minister's chief of staff said on Thursday.
  193. ^ "Cyprus finds first cases of Indian COVID variant". Reuters. 19 May 2021. Retrieved 19 May 2021.
  194. ^ "First case of Indian variant detected at Tocumen International". ndtv.com. 8 May 2021. Retrieved 14 May 2021.
  195. ^ "PANGO lineages Lineage B.1.617". cov-lineages.org. Retrieved 26 May 2021.
  196. ^ SARS-CoV-2 variants of concern and variants under investigation in England - Technical briefing 10 (PDF) (Report). London. Public Health England. 7 May 2021. Retrieved 7 May 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  197. ^ "British scientists warn over Indian coronavirus variant". Reuters. 7 May 2021. Retrieved 7 May 2021.
  198. ^ Davis, Nicola (7 May 2021). "Indian Covid variant is 'of concern', says Public Health England". The Guardian. London. Retrieved 7 May 2021.
  199. ^ "Confirmed cases of COVID-19 variants identified in UK". www.gov.uk. 3 June 2021. Retrieved 3 June 2021.   This article incorporates text published under the British Open Government Licence v3.0:
  200. ^ "Confirmed cases of COVID-19 variants identified in UK". www.gov.uk. 11 June 2021. from the original on 11 June 2021. Retrieved 11 June 2021.
January 19, 2024
sars, delta, variant, lineage, sars, kappa, variant, this, article, about, variant, virus, that, causes, covid, confused, with, deltacoronavirus, grouping, coronavirus, species, that, affects, birds, human, mammals, this, article, needs, updated, please, help,. For lineage B 1 617 1 see SARS CoV 2 Kappa variant This article is about a variant of the virus that causes COVID 19 It is not to be confused with the Deltacoronavirus grouping of coronavirus species that affects birds and non human mammals This article needs to be updated Please help update this article to reflect recent events or newly available information December 2021 The Delta variant B 1 617 2 was 3 4 a variant of SARS CoV 2 the virus that causes COVID 19 It was first detected in India on 5 October 2020 The Delta variant was named on 31 May 2021 and had spread to over 179 countries by 22 November 2021 The World Health Organization WHO indicated in June 2021 that the Delta variant was becoming the dominant strain globally 5 SARS CoV 2 VariantScientifically accurate atomic model of the external structure of SARS CoV 2 Each ball is an atom General detailsSymptomsNone Headache 1 2 Sore throat 1 Running nose 1 2 Fever 1 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 vteIt has mutations in the gene encoding the SARS CoV 2 spike protein 6 causing the substitutions T478K P681R and L452R 7 8 which are known to affect transmissibility of the virus as well as whether it can be neutralised by antibodies for previously circulating variants of the COVID 19 virus 9 In August 2021 Public Health England PHE reported secondary attack rate in household contacts of non travel or unknown cases for Delta to be 10 8 vis a vis 10 2 for the Alpha variant 10 the case fatality rate for those 386 835 people with Delta is 0 3 where 46 of the cases and 6 of the deaths are unvaccinated and below 50 years old 11 Immunity from previous recovery 12 13 or COVID 19 vaccines are effective in preventing severe disease or hospitalisation from infection with the variant 14 On 7 May 2021 PHE changed their classification of lineage B 1 617 2 from a variant under investigation VUI to a variant of concern VOC based on an assessment of transmissibility being at least equivalent to B 1 1 7 Alpha variant 15 the UK s SAGE using May data estimated a realistic possibility of being 50 more transmissible 16 On 11 May 2021 the WHO also classified this lineage VOC and said that it showed evidence of higher transmissibility and reduced neutralisation On 15 June 2021 the Centers for Disease Control and Prevention CDC declared Delta a variant of concern 17 The variant is thought to be partly responsible for India s deadly second wave of the pandemic beginning in February 2021 18 19 20 It later contributed to a third wave in Fiji the United Kingdom 21 22 23 and South Africa 24 and the WHO warned in July 2021 that it could have a similar effect elsewhere in Europe and Africa 25 24 By late July it had also driven an increase in daily infections in parts of Asia 26 the United States 27 Australia and New Zealand 28 Contents 1 Classification 1 1 Names 1 2 Other sublineages of B 1 617 1 3 Mutations 1 4 Lineages 1 4 1 Delta plus variant 2 Symptoms 3 Prevention 4 Treatment 5 Epidemiology 5 1 Transmissibility 5 2 Infection age groups 5 3 Virulence 6 Statistics 7 History 7 1 Government responses 8 Extinction 9 See also 10 Notes 11 References 12 External linksClassificationThe Delta variant has mutations in the gene encoding the SARS CoV 2 spike protein 6 causing the substitutions D614G T478K P681R and L452R 29 8 It is identified as the 21A 21I and 21J clades under the Nextstrain phylogenetic classification system 30 Names The virus has also been referred to by the term Indian Variant 31 as it was originally detected in India However the Delta variant is only one of three variants of the lineage B 1 617 all of which were first detected in India 32 At the end of May 2021 the WHO assigned the label Delta to lineage B 1 617 2 after introducing a new policy of using Greek letters for variants of concern and variants of interest 33 Other sublineages of B 1 617 There are three sublineages of lineage B 1 617 categorised so far B 1 617 1 Kappa variant was designated a Variant Under Investigation in April 2021 by Public Health England Later in April 2021 two other variants B 1 617 2 and B 1 617 3 were designated as Variants Under Investigation While B 1 617 3 shares the L452R and E484Q mutations found in B 1 617 1 B 1 617 2 lacks the E484Q mutation B 1 617 2 has the T478K mutation not found in B 1 617 1 and B 1 617 3 34 35 Simultaneously the ECDC released a brief maintaining all three sublineages of B 1 617 as VOI estimating that a greater understanding of the risks related to these B 1 617 lineages is needed before any modification of current measures can be considered 36 Mutations nbsp Amino acid mutations of SARS CoV 2 Delta variant plotted on a genome map of SARS CoV 2 with a focus on Spike 37 Defining mutations in theSARS CoV 2 Delta variant Gene Nucleotide Amino acidORF1b P314LP1000LSpike G142DT19RR158GL452RT478KD614GP681RD950NE156delF157delM I82TN D63GR203MD377YORF3a S26LORF7a V82AT120ISources CDC 38 Covariants org 39 The Delta B 1 617 2 genome has 13 mutations 15 or 17 according to some sources which depending on whether more common mutations are included which produce alterations in the amino acid sequences of the proteins it encodes 40 The list of spike protein mutations is 19R G142D D156 157 R158G L452R T478K D614G P681R D950N according to GVN 41 or T19R G142D del 156 157 R158G L452R T478K D614G P681R according to Genscript 42 Four of them all of which are in the virus s spike protein code are of particular concern D614G The substitution at position 614 an aspartic acid to glycine substitution is shared with other highly transmissible variants like Alpha Beta and Gamma 9 T478K 9 29 The exchange at position 478 is a threonine to lysine substitution 43 L452R The substitution at position 452 a leucine to arginine substitution confers stronger affinity of the spike protein for the ACE2 receptor 44 and decreased recognition capability of the immune system 8 45 P681R The substitution at position 681 a proline to arginine substitution which according to William A Haseltine may boost cell level infectivity of the variant by facilitating cleavage of the S precursor protein to the active S1 S2 configuration 46 The E484Q mutation is not present in the B 1 617 2 genome 46 47 Lineages As of August 2021 Delta variants have been subdivided in the Pango lineage designation system into variants from AY 1 to AY 28 However there is no information on whether such classification correlates with biological characteristic changes of the virus 48 It is said that as of August 2021 AY 4 to AY 11 are predominant in the UK AY 12 in Israel AY 2 AY 3 AY 13 AY 14 AY 25 in the US AY 20 in the US and Mexico AY 15 in Canada AY 16 in Kenya AY 17 in Ireland and Northern Ireland AY 19 in South Africa AY 21 in Italy and Switzerland AY 22 in Portugal AY 24 in Indonesia and AY 23 in Indonesia Singapore Japan and South Korea 49 Delta plus variant See also Variants of SARS CoV 2 Delta lineage B 1 617 2 Delta with K417N originally corresponded to lineages AY 1 and AY 2 50 subsequently also lineage AY 3 51 and has been nicknamed Delta plus or Nepal variant 52 It has the K417N mutation 53 which is also present in the Beta variant 54 The exchange at position 417 is a lysine to asparagine substitution 55 As of mid October 2021 the AY 3 variant accounted for a cumulative prevalence of approximately 5 in the United States and 2 worldwide 56 In mid October the AY 4 2 Delta sublineage was expanding in England and being monitored and assessed It contains mutations A222V and Y145H in its spike protein 57 not considered of particular concern It has been suggested that AY 4 2 might be 10 15 more transmissible than the original Delta variant Mid October 2021 AY 4 2 accounted for an estimated 10 of cases and has led to an additional growth rate rising to about 1 10 of 10 per generational time of five days or so This additional growth rate would grow with increasing prevalence Without AY 4 2 and no other changes the number of cases in the UK would have been about 10 lower 58 AY 4 2 grows about 15 faster per week 59 In the UK it was reclassified as a variant under investigation but not of concern in late October 2021 60 In Denmark after a drop in AY 4 2 cases a new fast surge was detected and monitored but was not yet considered a cause of concern 61 62 SymptomsMain article Symptoms of COVID 19 The most common symptoms may have changed from the most common symptoms previously associated with standard COVID 19 Infected people may mistake the symptoms for a bad cold and not realize they need to isolate Common symptoms reported have been headaches sore throat a runny nose or a fever 1 medical citation needed 2 PreventionSee also COVID 19 Prevention Oxford AstraZeneca COVID 19 vaccine Effectiveness Pfizer BioNTech COVID 19 vaccine Effectiveness Moderna COVID 19 vaccine Effectiveness Janssen COVID 19 vaccine Clinical trials Sinopharm BIBP COVID 19 vaccine Variants Sputnik V COVID 19 vaccine Effectiveness CoronaVac Variants Covaxin Efficacy ZF2001 Efficacy and Abdala vaccine Efficacy Summary of vaccine protection against Delta WHO s update 24 August 2021 63 Disease or infection Severe protection retainedSymptomatic possibly reduced protectionSevere disease nbsp AstraZeneca Vaxzevria 1 Moderna 1 Pfizer BioNTech 2 Symptomatic disease nbsp to nbsp Pfizer BioNTech 3 nbsp Covaxin 1 nbsp nbsp AstraZeneca Vaxzevria 2 Infection nbsp AstraZeneca Vaxzevria 1 Pfizer BioNTech 1 Symbols indicate the magnitude of vaccine effectiveness VE reduction Note that VE reduction doesn t mean loss of protection because original high protection rate such as 95 with some reduction such as 10 would still retain protection such as 85 Enclosed in parentheses is the number of studies supporting the indication Studies vary in population outcome definitions study design etc which may explain differences in VE estimates for a product in different studies Also the reductions represent VE estimates and do not represent uncertainties around the estimates which may vary substantially across studies The VE reductions should be interpreted with these limitations nbsp VE reduces lt 10 or VE gt 90 without comparator nbsp VE reduces between 10 and lt 20 nbsp nbsp VE reduces between 20 and lt 30 Effects on neutralization fully vaccinated 64 nbsp to nbsp Anhui ZIFIVAX 2 Covaxin 3 nbsp Janssen 3 Moderna 3 Covishield 2 nbsp to nbsp nbsp AstraZeneca Vaxzevria 4 Pfizer BioNTech 8 nbsp nbsp Moderna amp Pfizer BioNTech 1 nbsp to nbsp nbsp nbsp Coronavac 2 Symbols indicate the magnitude of neutralization reduction with full vaccination Enclosed in parentheses is the number of studies supporting the indication nbsp Neutralization reduces lt 2 fold nbsp Neutralization reduces 2 to lt 5 fold nbsp nbsp Neutralization reduces 5 to lt 10 fold nbsp nbsp nbsp Neutralization reduces 10 fold Moderna amp Pfizer BioNTech were evaluated together WHO has not issued preventative measures against Delta specifically non pharmaceutical measures recommended to prevent wild type COVID 19 should still be effective These would include washing hands wearing a mask maintaining distance from others avoiding touching the mouth nose or eyes avoiding crowded indoor spaces with poor ventilation especially where people are talking going to get tested if one develops symptoms and isolating if one becomes sick 65 Public Health authorities should continue to find infected individuals using testing trace their contacts and isolate those who have tested positive or been exposed 66 Event organizers should assess the potential risks of any mass gathering and develop a plan to mitigate these risks 67 See also Non pharmaceutical intervention epidemiology The Indian Council of Medical Research ICMR found that convalescent sera of the COVID 19 cases and recipients of Bharat Biotech s BBV152 Covaxin were able to neutralise VUI B 1 617 although with a lower efficacy 68 Anurag Agrawal the director of the Institute of Genomics and Integrative Biology IGIB said the study on the effectiveness of the available vaccines on lineage B 1 617 suggests that post vaccination the infections are milder 69 Anthony Fauci the Chief Medical Advisor to the President of the United States has also expressed his confidence regarding the preliminary results In an interview on 28 April he said This is something where we re still gaining data daily But the most recent data was looking at convalescent sera of COVID 19 cases and people who received the vaccine used in India the Covaxin It was found to neutralise the 617 variants 70 Another study by the Centre for Cellular and Molecular Biology CCMB in Hyderabad found Covishield Oxford AstraZeneca vaccinated sera offers protection against lineage B 1 617 71 A study conducted by Public Health England PHE found that compared to those who were unvaccinated those who were vaccinated with either the Pfizer BioNTech or AstraZeneca Oxford had 33 less instances of symptomatic disease caused by the variant after the first dose Among those who were two weeks after the receiving their second dose of the Pfizer BioNTech vaccine 88 less subjects had symptomatic disease from the Delta variant versus those that were unvaccinated Among those who were two weeks after the receiving their second dose of the AstraZeneca Oxford vaccine 60 less subjects had symptomatic disease from the Delta variant versus those that were unvaccinated 72 73 A study by a group of researchers from the Francis Crick Institute published in The Lancet shows that humans fully vaccinated with the Pfizer BioNTech vaccine are likely to have more than five times lower levels of neutralizing antibodies against the Delta variant compared to the original COVID 19 strain 74 75 In June 2021 PHE announced it had conducted a study which found that after two shots the Pfizer BioNTech vaccine and the AstraZeneca vaccine are respectively 96 and 92 effective at preventing hospitalisation from the Delta variant 76 77 On July 3 researchers from the universities of Toronto and Ottawa in Ontario Canada released a preprint study suggesting that the Moderna vaccine may be effective against death or hospitalization from the Delta variant 78 unreliable medical source In a study of the University of Sri Jayewardenepura in July 2021 found the Sinopharm BIBP vaccine caused seroconversion in 95 of individuals studied that had received both doses of the vaccine The rate was higher in 20 39 age group 98 9 but slightly lower in the over 60 age group 93 3 Neutralising antibodies were present among 81 25 of the vaccinated individuals studied 79 80 On 29 June 2021 the director of the Gamaleya Institute Denis Logunov said that Sputnik V is about 90 effective against the Delta variant 81 On July 21 researchers from PHE published a study finding that the Pfizer vaccine was 93 7 effective against symptomatic disease from Delta after 2 doses while the Astrazeneca vaccine was 67 effective 82 On August 2 several experts expressed concern that achieving herd immunity may not currently be possible because the Delta variant is transmitted among those immunized with current vaccines 83 On August 10 a study showed that the full vaccination coverage rate is correlated inversely to the SARS CoV 2 delta variant mutation frequency in 16 countries R squared 0 878 Data strongly indicates that full vaccination against COVID 19 may slow down virus evolution 84 TreatmentSee also Treatment and management of COVID 19 In vitro experiments suggest that bamlanivimab may not be effective against Delta on its own 85 At high enough concentrations casirivimab etesevimab and imdevimab appear to still be effective A preprint study suggests that sotrovimab may also be effective against Delta 86 Doctors in Singapore have been using supplemental oxygen remdesivir and corticosteroids on more Delta patients than they did on previous variants 87 EpidemiologySummary of impacts for Delta WHO s update 24 August 2021 63 Transmissibility Increased transmissibility and secondary attack rate similar transmissibility between vaccinated and unvaccinated individuals Virulence Increased risk of hospitalizationReinfection Decreased neutralizing activityDiagnostics No impacts yet reported Generalized finding compared to other strains based on evidence including non peer reviewed publications Transmissibility UK scientists have said that the Delta variant is between 40 and 60 more transmissible than the previously dominant Alpha variant which was first identified in the UK as the Kent variant 88 Given that Alpha is already 150 as transmissible as the original SARS CoV 2 strain that emerged in late 2019 in Wuhan 88 and if Delta is 150 as transmissible as Alpha then Delta may be 225 as transmissible as the original strain 89 BBC reported that R 0 displaystyle R 0 nbsp basic reproduction number or the expected number of cases directly generated by one case in a population where all individuals are susceptible to infection for the first detected SARS CoV 2 virus is 2 4 2 6 whereas Alpha s reproduction number is 4 5 and Delta s is 5 9 90 91 These basic reproduction numbers can be compared to MERS 0 29 0 80 92 seasonal influenza 1 2 1 4 93 Ebola 1 4 1 8 94 common cold 2 3 95 SARS 2 4 96 smallpox 3 5 6 97 and chickenpox 10 12 98 Due to Delta s high transmissibility even those that are vaccinated are vulnerable 99 albeit to a lesser extent 73 A study 100 published online not peer reviewed by Guangdong Provincial Center for Disease Control and Prevention may partly explain the increased transmissibility people with infection caused by Delta had 1 000 times more copies of the virus in the respiratory tracts than those with infection caused by variants first identified in the beginning of the pandemic and it took on average 4 days for people infected with Delta for the virus to be detectable compared to 6 days with initially identified variants 101 102 Surveillance data from the U S Germany and the Netherlands indicates the Delta variant is growing by about a factor of 4 every two weeks with respect to the Alpha variant 103 104 105 In India the United Kingdom 106 Portugal 107 Russia 108 Mexico Australia Indonesia 109 South Africa Germany 110 Luxembourg 111 the United States 112 the Netherlands 113 Denmark 114 France 115 and probably many other countries the Delta variant had become the dominant strain by July 2021 Depending on country there is typically a lag from a few days to several weeks between cases and variant reporting As of July 20 this variant had spread to 124 countries 64 and WHO had indicated that it was becoming the dominant strain if not one already 116 In the Netherlands the virus was still able to propagate significantly in the population with over 93 4 of blood donors being tested positive for SARS CoV 2 antibodies after week 28 2021 Many people there are not fully vaccinated so those antibodies would have been developed from exposure to the wild virus or from a vaccine 117 118 Similar high seroimmunity levels occur in the United Kingdom in blood donors and general surveillance 119 120 121 A preprint found that the viral load in the first positive test of infections with the variant was on average 1000 times higher than with compared infections during 2020 122 123 Preliminary data from a study with 100 000 volunteers in the UK from May to July 2021 when Delta was spreading rapidly indicates that vaccinated people who test positive for COVID 19 including asymptomatic cases have a lower viral load in average Data from the US UK and Singapore indicate that vaccinated people infected by Delta may have viral loads as high as unvaccinated infected people but might remain infectious for a shorter period 124 Infection age groups Surveillance data from the Indian government s Integrated Disease Surveillance Programme IDSP shows that around 32 of patients both hospitalised and outside hospitals were aged below 30 in the second wave compared to 31 during the first wave among people aged 30 40 the infection rate stayed at 21 Hospitalisation in the 20 39 bracket increased to 25 5 from 23 7 while the 0 19 range increased to 5 8 from 4 2 The data also showed a higher proportion of asymptomatic patients were admitted during the second wave with more complaints of breathlessness 125 Virulence See also Virulence A few early studies suggest the Delta variant causes more severe illness than other strains 126 On 7 June 2021 researchers at the National Centre for Infectious Diseases in Singapore posted a paper suggesting that patients testing positive for Delta are more likely to develop pneumonia and or require oxygen than patients with wild type or Alpha 127 On June 11 Public Health England released a report finding that there was significantly increased risk of hospitalization from Delta as compared with Alpha 128 the risk was approximately twice as high for those infected with the Delta variant 129 On June 14 researchers from Public Health Scotland found that the risk of hospitalization from Delta was roughly double that of from Alpha 130 On July 7 a preprint study from epidemiologists at the University of Toronto found that Delta had a 120 greater or more than twice as large risk of hospitalization 287 greater risk of ICU admission and 137 greater risk of death compared to non variant of concern strains of SARS COV 2 131 However on July 9 Public Health England reported that the Delta variant in England had a case fatality rate CFR of 0 2 while the Alpha variant s case fatality rate was 1 9 although the report warns that case fatality rates are not comparable across variants as they have peaked at different points in the pandemic and so vary in background hospital pressure vaccination availability and rates and case profiles treatment options and impact of reporting delay among other factors 132 James McCreadie a spokesperson for Public Health England clarified It is too early to assess the case fatality ratio compared to other variants 133 A Canadian study released on 5 October 2021 revealed that the Delta variant caused a 108 percent rise in hospitalization 235 percent increase in ICU admission and a 133 percent surge in death compared to other variants is more serious and resulted in an increased risk of death compared to previous variants odds that are significantly decreased with immunization 134 135 StatisticsThe chance of detecting a Delta case varies significantly especially depending on a country s sequencing rate less than 0 05 of all COVID 19 cases have been sequenced in the lowest sequencing countries to around 50 percent in the highest 136 137 By 22 June 2021 needs update more than 4 500 sequences of the variant had been detected in about 78 countries 138 139 140 Reported numbers of sequences in countries with detections are Cases by country viewtalkedit Country Area Confirmed cases PANGOLIN 141 as of 19 December Confirmed cases GISAID 138 as of 23 November Cases other sources as of 19 January 2022 First detection Last detection nbsp United Kingdom 985 491 826 465 1 625 557 142 22 February 2021 nbsp United States 1 099 811 947 472 99 4 of cases 143 23 February 2021 nbsp Canada 78 412 62 008 196 866 144 15 March 2021 nbsp Germany 150 416 117 513 1 March 2021 nbsp Denmark 138 336 89 706 8 March 2021 nbsp Japan 86 383 70 973 86 037 145 146 28 March 2021 nbsp France 75 224 70 822 21 February 2021 nbsp Turkey 54 134 50 578 5 147 28 April 2021 nbsp Fiji 495 507 47 639 148 149 150 19 April 2021 nbsp India 45 638 45 055 5 October 2020 nbsp Switzerland 48 304 38 003 29 March 2021 nbsp Sweden 46 018 37 773 26 March 2021 nbsp Belgium 37 334 31 611 25 March 2021 nbsp Italy 33 642 29 282 2 April 2021 nbsp Spain 30 618 28 257 22 April 2021 nbsp The Netherlands 33 128 27 870 6 April 2021 nbsp Australia 23 696 22 715 25 750 151 16 March 2021 nbsp Ireland 22 425 21 061 26 February 2021 nbsp Brazil 27 733 17 987 1051 152 153 20 May 2021 154 155 156 157 158 nbsp Mexico 20 230 17 710 5 April 2021 nbsp Slovenia 16 334 13 439 20 April 2021 nbsp Israel 15 787 12 259 41 159 160 161 16 April 2021 nbsp Norway 15 716 12 130 1 162 15 April 2021 nbsp Portugal 12 984 11 983 5 April 2021 nbsp South Africa 2 582 10 619 4 163 30 April 2021 nbsp Poland 16 484 10 320 16 164 26 April 2021 nbsp Lithuania 899 9 070 1 165 17 June 2021 nbsp Finland 1 570 8 733 2 876 166 167 168 169 18 March 2021 nbsp Czech Republic 11 225 8 487 24 April 2021 nbsp Singapore 2 727 7 510 26 February 2021 nbsp Slovakia 353 7 146 15 June 2021 nbsp Philippines 870 3 220 8 612 170 171 11 May 2021 nbsp South Korea 706 6 497 26 March 2021 nbsp Croatia 479 6 165 11 June 2021 nbsp Chile 64 5 858 13 June 2021 nbsp Luxembourg 1 153 5 515 15 April 2021 nbsp Indonesia 1 623 4 980 3 April 2021 nbsp Romania 294 4 655 26 April 2021 nbsp Bulgaria 231 4 614 5 April 2021 nbsp Russia 1 468 4 295 16 172 21 April 2021 nbsp Thailand 236 4 293 2 173 24 April 2021 nbsp Iceland 3 767 30 August 2021 nbsp Malaysia 146 3 624 10 April 2021 nbsp Austria 1 578 3 622 17 April 2021 nbsp New Zealand 92 2 844 107 174 175 9 March 2021 nbsp Estonia 2 740 21 July 2021 nbsp Greece 17 2 642 23 March 2021 nbsp Peru 6 2 580 10 June 2021 nbsp Bahrain 117 2 013 5 April 2021 nbsp Nigeria 36 1 795 1 176 7 August 2021 nbsp Kenya 256 1 700 5 176 177 17 July 2021 nbsp Aruba 90 1 592 16 April 2021 nbsp Vietnam 54 1 414 12 178 179 18 April 2021 nbsp Puerto Rico 1 355 1 360 9 September 2021 nbsp Qatar 121 1 343 19 April 2021 nbsp Bangladesh 283 1 273 9 180 181 28 April 2021 nbsp Sint Maarten 1 225 1 231 19 March 2021 nbsp Ecuador 955 1 023 20 July 2021 nbsp Sri Lanka 117 984 1 182 30 April 2021 nbsp Colombia 974 3 July 2021 nbsp Botswana 196 912 2 183 28 April 2021 nbsp Gibraltar 835 848 5 September 2021 nbsp Kosovo 829 834 2 May 2021 nbsp Reunion 54 754 4 May 2021 nbsp Cambodia 171 733 5 April 2021 nbsp Papua New Guinea 710 717 10 August 2021 nbsp Costa Rica 35 689 7 July 2021 nbsp Pakistan 49 676 16 May 2021 nbsp China 520 536 24 April 2021 nbsp Maldives 6 525 31 July 2021 nbsp Ghana 101 522 20 April 2021 nbsp Curacao 467 23 April 2021 nbsp Bonaire 458 13 July 2021 nbsp Bosnia and Herzegovina 31 430 26 July 2021 nbsp Ethiopia 424 16 August 2021 nbsp Seychelles 407 30 September 2021 nbsp Argentina 4 385 2 184 24 April 2021 nbsp Martinique 8 365 10 August 2021 nbsp Guadeloupe 362 10 March 2021 nbsp Jordan 5 360 21 April 2021 nbsp Uganda 134 340 1 185 26 March 2021 nbsp Zambia 82 326 29 May 2021 nbsp Gambia 42 316 12 July 2021 nbsp Mozambique 314 16 July 2021 nbsp Guatemala 4 302 29 July 2021 nbsp Rwanda 91 283 9 July 2021 nbsp Cameroon 282 28 September 2021 nbsp Georgia country 19 272 15 May 2021 nbsp French Guiana 53 264 22 July 2021 nbsp U S Virgin Islands 247 18 August 2021 nbsp Nepal 100 238 9 186 28 April 2021 nbsp DR Congo 19 228 5 176 3 May 2021 nbsp Malawi 5 213 30 April 2021 nbsp Kuwait 108 191 5 June 2021 nbsp Montenegro 178 8 August 2021 nbsp Ukraine 13 170 24 June 2021 nbsp Kazakhstan 167 19 August 2021 nbsp Oman 8 159 17 May 2021 nbsp Angola 6 159 14 January 2021 nbsp Hong Kong 153 145 22 April 2021 nbsp Suriname 150 3 August 2021 nbsp Morocco 3 138 2 187 3 May 2021 nbsp Togo 130 31 July 2021 nbsp Trinidad and Tobago 114 3 August 2021 nbsp Namibia 110 June 2021 nbsp Paraguay 4 100 8 July 2021 nbsp Belize 98 30 June 2021 nbsp Egypt 98 15 July 2021 nbsp Zimbabwe 96 26 July 2021 nbsp Liechtenstein 95 15 July 2021 nbsp Senegal 13 93 6 May 2021 nbsp Republic of Congo 87 15 July 2021 nbsp Vastra Gotaland 86 19 July 2021 nbsp Eswatini 81 26 July 2021 nbsp Lebanon 80 3 July 2021 nbsp Latvia 22 73 27 May 2021 nbsp Monaco 34 70 15 May 2021 nbsp Mauritius 15 67 8 May 2021 nbsp Malta 42 63 23 June 2021 nbsp Guinea Bissau 62 3 November 2021 nbsp Burundi 3 57 31 May 2021 nbsp Antigua and Barbuda 57 6 August 2021 nbsp Liberia 56 10 July 2021 nbsp Armenia 50 5 August 2021 nbsp Uzbekistan 30 47 number unreported 188 25 June 2021 nbsp Benin 47 23 July 2021 nbsp North Macedonia 6 38 11 July 2021 nbsp The Bahamas 38 8 August 2021 nbsp Cayman Islands 37 30 July 2021 nbsp Myanmar 12 33 1 June 2021 nbsp Serbia 5 33 6 July 2021 nbsp Timor Leste 33 12 189 8 August 2021 nbsp South Sudan 29 7 June 2021 nbsp United Arab Emirates 28 23 June 2021 nbsp Brunei 28 17 August 2021 nbsp Gabon 27 2 August 2021 nbsp Mayotte 27 21 October 2021 nbsp Algeria 17 25 6 190 28 July 2021 nbsp Andorra 25 17 July 2021 nbsp Barbados 3 23 24 May 2021 nbsp Sierra Leone 22 8 September 2021 nbsp Iran 11 21 3 191 11 May 2021 nbsp Burkina Faso 21 21 April 2021 nbsp Crimea 21 1 July 2021 nbsp Afghanistan 20 24 May 2021 nbsp Northern Mariana Islands 2 19 7 July 2021 nbsp Central African Republic 17 14 August 2021 nbsp Taiwan 10 15 14 June 2021 nbsp Guam 14 26 April 2021 nbsp Dominican Republic 14 3 May 2021 nbsp Hungary 14 192 22 July 2021 nbsp Equatorial Guinea 14 30 August 2021 nbsp Iraq 2 13 27 April 2021 nbsp Moldova 11 11 6 July 2021 nbsp Albania 11 11 13 July 2021 nbsp Comoros 11 11 26 October 2021 nbsp Jamaica 10 10 23 July 2021 nbsp Anguilla 8 8 20 April 2021 nbsp Saint Lucia 7 7 26 July 2021 nbsp Montserrat 7 7 1 August 2021 nbsp Saint Barthelemy 7 7 17 August 2021 nbsp British Virgin Islands 5 5 27 July 2021 nbsp Cyprus 1 1 4 193 19 May 2021 nbsp Turks and Caicos Islands 4 4 12 July 2021 nbsp Azerbaijan 2 2 14 July 2021 nbsp Honduras 2 2 31 July 2021 nbsp El Salvador 2 2 2 August 2021 nbsp Saint Vincent and the Grenadines 2 2 8 August 2021 nbsp Mali 2 2 11 August 2021 nbsp Saudi Arabia 2 2 9 September 2021 nbsp Haiti 1 1 number unreported 188 27 July 2021 nbsp Panama 1 1 1 194 29 April 2021 nbsp Tunisia 1 1 21 May 2021 nbsp Sodermanland 1 1 7 July 2021 nbsp Venezuela 1 1 7 July 2021 nbsp Mongolia 1 1 23 September 2021 nbsp Kyrgyzstan 1 1 number unreported 188 16 May 2021 188 World 178 countries Total 3 119 592 solely B 1 617 2 Total 2 768 050 B 1 617 2 AY 1 AY 2 AY 3 Total 1 862 122HistoryThe first cases of the variant outside India were detected in late February 2021 including the United Kingdom on 22 February the United States on 23 February and Singapore on 26 February 195 40 138 British scientists at Public Health England redesignated the B 1 617 2 variant on 7 May 2021 as variant of concern VOC 21APR 02 196 after they flagged evidence in May 2021 that it spreads more quickly than the original version of the virus 21 Another reason was that they identified 48 clusters of B 1 617 2 some of which revealed a degree of community transmission 197 198 With cases from the Delta variant having risen quickly British scientists considered the Delta variant having overtaken the Alpha variant as the dominant variant of SARS CoV 2 in the UK in early June 2021 199 Researchers at Public Health England later found that over 90 of new cases in the UK in the early part of June 2021 were the Delta variant they also cited evidence that the Delta variant was associated with an approximately 60 increased risk of household transmission compared to the Alpha variant 200 Canada s first confirmed case of the variant was identified in Quebec on 21 April 2021 and later the same day 39 cases of the variant were identified in British Columbia 201 Alberta reported a single case of the variant on 22 April 2021 202 Nova Scotia reported two Delta variant cases in June 2021 203 Fiji also confirmed its first case of the variant on 19 April 2021 in Lautoka and has since then climbed up to 47 000 cases and counting 204 The variant has been identified as a super spreader and has led to the lockdowns of five cities Lautoka Nadi Suva Lami and Nausori an area which accounts for almost two thirds of the country s population On 29 April 2021 health officials from Finland s Ministry of Social Affairs and Health STM and the Finnish Institute for Health and Welfare THL reported that the variant had been detected in three samples dating back to March 2021 166 The Philippines confirmed its first two cases of the variant on 11 May 2021 despite the imposed travel ban of the country from the nations in the Indian subcontinent except for Bhutan and Maldives Both patients have no travel history from India for the past 14 days but instead from Oman and UAE 205 North Macedonia confirmed its first case of the variant on 7 June 2021 after a person who was recovering from the virus in Iraq was transported to North Macedonia In a laboratory test the variant was detected in the person On 22 June 2021 the country reported its second case of the Delta variant in a colleague of the first case who had also been in Iraq and who subsequently developed symptoms 206 The detection of B 1 617 was hampered in some countries by a lack of specialised kits for the variant and laboratories that can perform the genetic test 207 208 For example as of 18 May Pakistan had not reported any cases but authorities noted that 15 of COVID 19 samples in the country were of an unknown variant they could not say if it was B 1 617 because they were unable to test for it Other countries had reported travellers arriving from Pakistan that were infected with B 1 617 207 In June 2021 scientist Vinod Scaria of India s Institute of Genomics and Integrative Biology highlighted the existence of the B 1 617 2 1 variant also known as AY 1 or Delta plus which has an additional K417N mutation compared to the Delta variant 53 B 1 617 2 1 was detected in Europe in March 2021 and has since been detected in Asia and America 53 On 23 June 2021 the European Centre for Disease Prevention and Control ECDC warned that the variant would represent 90 of all new cases in the European Union by the end of August 209 By 3 July 2021 Delta became dominant in the US 210 On 9 July 2021 Public Health England issued Technical Briefing 18 on SARS CoV 2 variants documenting 112 deaths among 45 136 UK cases of SARS CoV 2 Delta variant with 28 days follow up with a fatality rate of 0 2 211 Briefing 16 notes that M ortality is a lagged indicator which means that the number of cases who have completed 28 days of follow up is very low therefore it is too early to provide a formal assessment of the case fatality of Delta stratified by age compared to other variants 212 Briefing 18 warns that Case fatality is not comparable across variants as they have peaked at different points in the pandemic and so vary in background hospital pressure vaccination availability and rates and case profiles treatment options and impact of reporting delay among other factors 211 The most concerning issue is the logistic growth rate of 0 93 week relative to Alpha This means that per week the number of Delta samples cases is growing by a factor of exp 0 93 2 5 with respect to the Alpha variant This results under the same infection prevention measures in a much greater case load over time until a large fraction of people have been infected by it 213 214 Government responses After the rise in cases from the second wave at least 20 countries imposed travel bans and restrictions on passengers from India in April and May UK prime minister Boris Johnson cancelled his visit to India twice while Japanese Prime Minister Yoshihide Suga postponed his April trip 215 216 217 In May 2021 residents of two tower blocks in Velbert Germany were quarantined after a woman in the building tested positive for the Delta variant 218 In May Delhi Chief Minister Arvind Kejriwal said that a new coronavirus variant from Singapore was extremely dangerous for children and could result in a third wave in India From 16 May to 13 June 2021 as well as 22 July 2021 to 10 August 2021 Singapore entered lockdowns known as Phase 2 Heightened Alert similar to 2020 On 14 June the British prime minister Boris Johnson announced that the proposed end of all restrictions on 21 June in the United Kingdom was delayed for up to four weeks and vaccination roll out was accelerated following concerns over the Delta variant which accounted for the vast majority 90 of new infections 219 UK scientists have said that the Delta variant is between 40 and 60 more transmissible than the previously dominant Alpha variant which was first identified in the UK as the Kent variant 220 On 23 June the province of Ontario in Canada accelerated 2nd dose vaccine appointments for people living in Delta hot spots such as Toronto Peel and Hamilton 221 On 25 June Israel restored their mask mandate citing the threat of Delta 222 On 28 June Sydney and Darwin went back into lockdown because of Delta outbreaks 223 South Africa banned indoor and outdoor gatherings apart from funerals imposed a curfew and banned the sale of alcohol 224 On 3 July the islands of Bali and Java in Indonesia went into emergency lockdown 225 On 8 July Japanese Prime Minister Yoshihide Suga announced that Tokyo would once again enter a state of emergency and that most spectators would be barred from attending the Olympics set to start there on 23 July 226 On 9 July Seoul South Korea ramped up restrictions urging people to wear masks outdoors and limiting the size of gatherings 227 On 12 July French President Emmanuel Macron announced that all health care workers will need to be vaccinated by 15 September and that France will start using health passports to enter bars cafes restaurants and shopping centres from August 228 Los Angeles announced it will require masks indoors starting 17 July 2021 229 The United Kingdom lifted most COVID 19 restrictions on 19 July despite a surge in cases as the Delta variant became dominant The government cited the protection and wide coverage of the COVID 19 vaccination programme although health experts expressed concern at the move 230 231 On 23 July Vietnam extended its lockdown of Ho Chi Minh City to 1 August and announced lockdown restrictions would be put in place in Hanoi affecting a third of the country s population The Delta variant had brought upon the country s largest outbreak to date after mostly successful containment measures throughout 2020 232 233 On 17 August New Zealand went into an alert level 4 lockdown following a positive case being reported in Auckland More cases soon followed in the Coromandel Peninsula 234 This was the first reported community transmission case in the country in 170 days since February 2021 235 ExtinctionIn October 2021 Dr Jenny Harries chief executive of the UK Health and Security Agency stated that previous circulating variants such as Alpha had disappeared and replaced by the Delta variant 236 In March 2022 the World Health Organization listed the Alpha Beta and Gamma variants as previously circulating citing lack of any detected cases in the prior weeks and months in part due to the dominance of the Delta variant and subsequent Omicron variant 237 However within a few months the Delta variant was listed as a previously circulated variant with countries such as Australia going 12 weeks without any detections of Delta 4 See also nbsp COVID 19 portal nbsp Medicine portal nbsp Viruses portalVariants of SARS CoV 2 Alpha Beta Gamma Epsilon Zeta Eta Theta Iota Kappa Lambda Mu Omicron Lineage B 1 617NotesReferences a b c d e Grover Natalie 14 June 2021 Delta variant Covid symptoms include headaches sore throat and runny nose The Guardian London Retrieved 30 June 2021 a b c Roberts Michelle 14 June 2021 Headache and runny nose linked to Delta variant BBC News London Retrieved 2 July 2021 Tracking SARS CoV 2 variants www who int Retrieved 17 August 2022 a b Variants of concern CDGN Retrieved 17 August 2022 Lovelace Berkeley Jr 18 June 2021 WHO says delta is becoming the dominant Covid variant globally CNBC Retrieved 1 November 2021 a b Shang Jian Yushun Wan Lou Chuming Ye Gang Geng Qibin Auerbach Ashley Fang Li 2020 Cell entry mechanisms of SARS CoV 2 Proceedings of the National Academy of Sciences 117 21 11727 11734 Bibcode 2020PNAS 11711727S doi 10 1073 pnas 2003138117 PMC 7260975 PMID 32376634 expert reaction to VUI 21APR 02 B 1 617 2 being classified by PHE as a variant of concern sciencemediacentre org 7 May 2021 Retrieved 18 June 2021 a b c Starr Tyler N Greaney Allison J Dingens Adam S Bloom Jesse D April 2021 Complete map of SARS CoV 2 RBD mutations that escape the monoclonal antibody LY CoV555 and its cocktail with LY CoV016 Cell Reports Medicine 2 4 100255 doi 10 1016 j xcrm 2021 100255 PMC 8020059 PMID 33842902 a b c SARS CoV 2 variants of concern as of 24 May 2021 European Centre for Disease Prevention and Control 30 April 2021 Retrieved 6 August 2021 Technical Briefing 20 SARS CoV 2 variants of concern and variants under investigation in England PDF 6 August 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 Technical Briefing 21 SARS CoV 2 variants of concern and variants under investigation in England PDF Public Health England 20 August 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 Sivan Gazit 25 August 2021 Comparing SARS CoV 2 natural immunity to vaccine induced immunity reinfections versus breakthrough infections medRxiv 10 1101 2021 08 24 21262415v1 The study in Israel tracked 46035 unvaccinated recovered and 46035 vaccinated people of the same age distribution to compare their infection occurrence in the follow up period 640 infections and 21 hospitalization in the vaccinated group and 108 infections and 4 hospitalizations in the recovered group were recorded Past Covid 19 reduces risk of reinfection from Delta variant more than Pfizer vaccine Bloomberg 27 August 2021 Burn Murdoch John Mancini Donato Paolo 9 July 2021 How effective are coronavirus vaccines against the Delta variant www ft com Retrieved 23 July 2021 Confirmed cases of COVID 19 variants identified in UK www gov uk 7 May 2021 Archived from the original on 7 May 2021 Retrieved 7 May 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 Is The Variant From India The Most Contagious Coronavirus Mutant On The Planet NPR 14 May 2021 cited Eighty ninth SAGE meeting on COVID 19 13 May 2021 Held via Video Teleconference PDF UK Government 13 May 2021 06 15 2021 Lab Advisory CDC Classifies SARS CoV 2 Variant B 1 617 2 Delta a Variant of Concern CDC 15 June 2021 WHO labels a Covid strain in India as a variant of concern here s what we know CNBC 11 May 2021 WHO says India Covid variant of global concern BBC News 11 May 2021 Narang Deepanshu 22 April 2021 COVID 19 The Second Wave May Not Be the Last but Which One Will Be The Wire Science Retrieved 20 May 2022 a b Mishra Swapnil Mindermann Soren Sharma Mrinank Whittaker Charles Mellan Thomas A Wilton Thomas Klapsa Dimitra Mate Ryan Fritzsche Martin Zambon Maria Ahuja Janvi 1 September 2021 Changing composition of SARS CoV 2 lineages and rise of Delta variant in England eClinicalMedicine 39 101064 doi 10 1016 j eclinm 2021 101064 ISSN 2589 5370 PMC 8349999 PMID 34401689 Callaway Ewen 22 June 2021 Delta coronavirus variant scientists brace for impact Nature 595 7865 17 18 Bibcode 2021Natur 595 17C doi 10 1038 d41586 021 01696 3 PMID 34158664 S2CID 235609029 Rob Picheta 30 June 2021 Britain thinks it can out vaccinate the Delta variant The world isn t so sure CNN Retrieved 2 July 2021 a b Health service buckling as third coronavirus wave fuelled by Delta variant sweeps across South Africa the Guardian 4 July 2021 Retrieved 7 July 2021 Ellyatt Holly 1 July 2021 New Covid wave could be imminent as delta variant sweeps Europe WHO says CNBC Retrieved 2 July 2021 Delta variant Which Asian countries are seeing rising cases BBC News 19 July 2021 Retrieved 23 July 2021 US in another pivotal moment as Delta variant drives surge in Covid cases the Guardian 23 July 2021 Retrieved 23 July 2021 New Zealand suspends quarantine free travel bubble with Australia ITV News 23 July 2021 Retrieved 23 July 2021 a b SARS CoV 2 Variant Classifications and Definitions CDC gov Centers for Disease Control and Prevention 11 February 2020 Retrieved 15 June 2021 Genomic epidemiology of novel coronavirus Global subsampling Filtered to B 1 617 nextstrain org Retrieved 5 May 2021 Covid Indian variant Where is it how does it spread and is it more infectious bbc com 7 June 2021 Weekly epidemiological update on COVID 19 27 April 2021 PDF World Health Organization 27 April 2021 Retrieved 7 September 2021 Covid WHO renames UK and other variants with Greek letters BBC News 31 May 2021 Retrieved 8 June 2021 SARS CoV 2 Variant Classifications and Definitions Centers for Disease Control and Prevention 12 May 2021 Retrieved 16 May 2021 Di Giacomo Simone Mercatelli Daniele Rakhimov Amir Giorgi Federico M 2021 Preliminary report on severe acute respiratory syndrome coronavirus 2 SARS CoV 2 Spike mutation T478K Journal of Medical Virology 93 9 5638 5643 doi 10 1002 jmv 27062 PMC 8242375 PMID 33951211 Threat Assessment Brief Emergence of SARS CoV 2 B 1 617 variants in India and situation in the EU EEA European Centre for Disease Prevention and Control 11 May 2021 Retrieved 17 May 2021 Spike Variants Delta variant aka B 1 617 2 24 June 2021 covdb stanford edu accessed 1 July 2021 SARS CoV 2 Variant Classifications and Definitions cdc gov Centers for Disease Control and Prevention 15 June 2021 Retrieved 18 June 2021 Dedicated 21A S 478K Nextstrain build covariants org 15 June 2021 Retrieved 19 June 2021 a b Expert reaction to cases of variant B 1 617 the Indian variant being investigated in the UK Science Media Centre Retrieved 20 April 2021 Delta B 1 617 2 GVN 10 May 2021 Retrieved 27 November 2021 SARS CoV 2 Spike protein S1 T19R G142D del 156 157 R158G L452R T478K D614G P681R His Tag Genscript Retrieved 28 November 2021 Greenwood Michael 30 March 2021 SARS CoV 2 mutation T478K spreading at alarming speed in Mexico Medical News Retrieved 15 June 2021 South Andrew M Diz Debra I Chappell Mark C 1 May 2020 COVID 19 ACE2 and the cardiovascular consequences American Journal of Physiology Heart and Circulatory Physiology 318 5 H1084 H1090 doi 10 1152 ajpheart 00217 2020 PMC 7191628 PMID 32228252 Zhang Wenjuan Davis Brian D Chen Stephanie S Sincuir Martinez Jorge M Plummer Jasmine T Vail Eric 6 April 2021 Emergence of a Novel SARS CoV 2 Variant in Southern California JAMA 325 13 1324 1326 doi 10 1001 jama 2021 1612 PMC 7879386 PMID 33571356 a b Haseltine William An Indian SARS CoV 2 Variant Lands In California More Danger Ahead Forbes Retrieved 20 April 2021 Hoffmann Markus Hofmann Winkler Heike Kruger Nadine Kempf Amy Nehlmeier Inga Graichen Luise Arora Prerna Sidarovich Anzhalika Moldenhauer Anna Sophie Winkler Martin S Schulz Sebastian Jack Hans Martin Stankov Metodi V Behrens Georg M N Pohlmann Stefan June 2021 SARS CoV 2 variant B 1 617 is resistant to Bamlanivimab and evades antibodies induced by infection and vaccination Cell Reports 36 3 109415 doi 10 1016 j celrep 2021 109415 ISSN 2211 1247 PMC 8238662 PMID 34270919 Collectively our study reveals that antibody evasion of B 1 617 may contribute to the rapid spread of this variant The RBD of the B 1 617 S protein harbors two mutations associated with L452R or suspected E484Q of antibody evasion Moreover E484K present the B 1 351 and P 1 variants confers antibody resistance Li et al 2021 and one could speculate that exchange E484Q might have a similar effect 感染 伝播性の増加や抗原性の変化が懸念される 新型コロナウイルス SARS CoV 2 の新規変異株について 第13報 Infection New variant of coronavirus SARS CoV 2 concerns as to increased infectivity transmission and changes in antigenicity niid go jp in Japanese National Institute of Infectious Diseases NIID 28 August 2021 Retrieved 5 September 2021 New AY lineages and an update to AY 4 AY 12 pango network PANGO Network 27 August 2021 Retrieved 5 September 2021 SARS CoV 2 variants of concern and variants under investigation in England technical briefing 16 PDF Briefing Public Health England 18 June 2021 GOV 8641 Retrieved 23 June 2021 CDPHE to update variant data to align with CDC Colorado Department of Public Health and Environment State of Colorado 17 August 2021 Retrieved 25 October 2021 AY 1 AY 2 and AY 3 commonly referred to as delta plus Cutler S 18 June 2021 Nepal variant what we ve learned so far The Conversation Retrieved 6 August 2021 a b c Delta plus New Covid variant identified experts say no cause of concern for now The Indian Express Press Trust of India 14 June 2021 Retrieved 23 June 2021 Sample Ian 3 June 2021 Nepal Covid variant does it exist and should we be concerned The Guardian Retrieved 23 June 2021 Tang Julian W Oliver T R 2021 Introduction of the South African SARS CoV 2 variant 501Y V2 into the UK The Journal of Infection 82 4 e8 e10 doi 10 1016 j jinf 2021 01 007 ISSN 0163 4453 PMC 7813514 PMID 33472093 AY 3 Lineage Report outbreak info Updates constantly SARS CoV 2 variants of concern and variants under investigation in England Technical briefing 25 PDF UK Health Security Agency 15 October 2021 Retrieved 26 October 2021 Davis Nicola 19 October 2021 Offshoot of Covid Delta variant on the rise in England The Guardian SARS CoV 2 variants of concern and variants under investigation in England technical briefing 29 PDF GOV UK Retrieved 30 October 2021 Roberts Michelle 22 October 2021 Delta Plus Covid variant may be more transmissible BBC News name Den nye Delta undervariant AY 4 2 viser ikke tegn pa nedsat vaccineeffektivitet www ssi dk in Danish Retrieved 14 November 2021 outbreak info outbreak info Retrieved 14 November 2021 a b Weekly epidemiological update on COVID 19 24 August 2021 World Health Organization 24 August 2021 a b Weekly epidemiological update on COVID 19 20 July 2021 World Health Organization 20 July 2021 Advice for Public WHO Retrieved 14 July 2021 Health Workers and Administrators WHO Retrieved 14 July 2021 Key planning recommendations for mass gatherings in the context of the current COVID 19 outbreak WHO Retrieved 14 July 2021 Yadav PD Sapkal GN Abraham P Ella R Deshpande G Patil DY et al 7 May 2021 Neutralization of variant under investigation B 1 617 with sera of BBV152 vaccinees Clinical Infectious Diseases 74 2 366 368 doi 10 1093 cid ciab411 PMID 33961693 Covishield Covaxin effective against Indian strain of coronavirus study suggests The Week Retrieved 27 April 2021 Covaxin found to neutralise 617 variant of COVID 19 says Dr Fauci The Hindu 28 April 2021 Covishield Covaxin effective against Indian strain of coronavirus study suggests ET HealthWorld ETHealthworld com The Economic Times 28 April 2021 Ellyatt Holly 24 May 2021 Two doses of Covid vaccines provide effective protection against variant found in India Study CNBC a b Bernal Jamie Lopez Andrews Nick Gower Charlotte Gallagher Eileen Simmons Ruth Thelwall Simon et al 24 May 2021 Effectiveness of COVID 19 vaccines against the B 1 617 2 variant medRxiv 10 1101 2021 05 22 21257658v1 Wall Emma C Wu Mary Harvey Ruth Kelly Gavin Warchal Scott Sawyer Chelsea et al June 2021 Neutralising antibody activity against SARS CoV 2 VOCs B 1 617 2 and B 1 351 by BNT162b2 vaccination The Lancet 397 10292 2331 2333 doi 10 1016 s0140 6736 21 01290 3 ISSN 0140 6736 PMC 8175044 PMID 34090624 COVID 19 vaccine Pfizer jabs not the best for Delta variant says Lancet study The New Indian Express 5 June 2021 Vaccines highly effective against hospitalisation from Delta variant www gov uk Public Health England 14 June 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 UK study finds vaccines offer high protection against hospitalisation from Delta variant Reuters 14 June 2021 Retrieved 15 June 2021 Nasreen S He S Chung H Brown KA Gubbay JB Buchan SA et al 3 July 2021 Effectiveness of COVID 19 vaccines against variants of concern Canada medRxiv 10 1101 2021 06 28 21259420v1 Over 95 individuals developed antibodies against the Sinopharm vaccine USJ Researchers USJ University of Sri Jayewardenepura Sri Lanka 20 July 2021 Retrieved 20 July 2021 Jeewandara Chandima Aberathna Inoka Sepali Pushpakumara Pradeep Dharshana Kamaladasa Achala Guruge Dinuka Jayathilaka Deshni Gunesekara Banuri Tanussiya Shyrar Kuruppu Heshan Ranasinghe Thushali Dayarathne Shashika 19 July 2021 Antibody and T cell responses to Sinopharm BBIBP CorV in naive and previously infected individuals in Sri Lanka medRxiv 10 1101 2021 07 15 21260621v1 Russia s Sputnik V shot around 90 effective against Delta variant developers say Reuters 29 June 2021 Retrieved 11 August 2021 Lopez Bernal Jamie Andrews Nick Gower Charlotte Gallagher Eileen Simmons Ruth Thelwall Simon Stowe Julia Tessier Elise Groves Natalie Dabrera Gavin Myers Richard Campbell Colin N J Amirthalingam Gayatri Edmunds Matt Zambon Maria Brown Kevin E Hopkins Susan Chand Meera Ramsay Mary 2021 Effectiveness of Covid 19 Vaccines against the B 1 617 2 Delta Variant New England Journal of Medicine 385 7 585 594 doi 10 1056 NEJMoa2108891 ISSN 0028 4793 PMC 8314739 PMID 34289274 Dyer Owen 2 August 2021 Covid 19 Delta infections threaten herd immunity vaccine strategy BMJ 374 n1933 doi 10 1136 bmj n1933 ISSN 1756 1833 PMID 34340962 S2CID 236778544 Yeh TY Contreras GP 10 August 2021 Full vaccination suppresses SARS CoV 2 delta variant mutation frequency medRxiv 10 1101 2021 08 08 21261768v2 Delphine Planas 8 July 2021 Reduced sensitivity of SARS CoV 2 variant Delta to antibody neutralization Nature 596 7871 276 280 Bibcode 2021Natur 596 276P doi 10 1038 s41586 021 03777 9 PMID 34237773 S2CID 235775860 Andrea Cathcart 26 July 2021 The dual function monoclonal antibodies VIR 7831 and VIR 7832 demonstrate potent in vitro and in vivo activity against SARS CoV 2 bioRxiv doi 10 1101 2021 03 09 434607 S2CID 232223983 Retrieved 30 July 2021 Sean Wei Xiang Ong 7 June 2021 Clinical and Virological Features of SARS CoV 2 Variants of Concern A Retrospective Cohort Study Comparing B 1 1 7 Alpha B 1 315 Beta and B 1 617 2 Delta SSRN 3861566 a b How Dangerous Is the Delta Variant and Will It Cause a COVID Surge in the U S Scientific American 29 June 2021 cited SPI M O Consensus Statement on COVID 19 PDF UK Government 2 June 2021 Archived PDF from the original on 20 July 2021 Aubrey Allison Simmons Duffin Selena 17 July 2021 With The Delta Variant Spreading Fast Is It Time To Mask Up Again NPR Archived from the original on 2 August 2021 cited Doucleff Michaeleen 14 May 2021 Is The Variant From India The Most Contagious Coronavirus Mutant On The Planet NPR Archived from the original on 2 August 2021 Kollmeyer Barbara 30 July 2020 As transmissible as chickenpox Here s the CDC report on the delta variant that led to new mask policy MarketWatch Archived from the original on 2 August 2021 Retrieved 3 August 2021 Gallagher James 12 June 2021 Covid Is there a limit to how much worse variants can get BBC News Archived from the original on 3 August 2021 Kucharski AJ Althaus CL June 2015 The role of superspreading in Middle East respiratory syndrome coronavirus MERS CoV transmission Euro Surveillance 20 25 14 8 doi 10 2807 1560 7917 ES2015 20 25 21167 PMID 26132768 Chowell G Miller MA Viboud C June 2008 Seasonal influenza in the United States France and Australia transmission and prospects for control Epidemiology and Infection Cambridge University Press 136 6 852 64 doi 10 1017 S0950268807009144 PMC 2680121 PMID 17634159 The reproduction number across influenza seasons and countries lied in the range 0 9 2 0 with an overall mean of 1 3 and 95 confidence interval CI 1 2 1 4 Wong ZS Bui CM Chughtai AA Macintyre CR April 2017 A systematic review of early modelling studies of Ebola virus disease in West Africa Epidemiology and Infection 145 6 1069 1094 doi 10 1017 S0950268817000164 PMC 9507849 PMID 28166851 The median of the R0 mean estimate for the ongoing epidemic overall is 1 78 interquartile range 1 44 1 80 Freeman C 6 November 2014 Magic formula that will determine whether Ebola is beaten The Telegraph Telegraph Co Uk Archived from the original on 11 January 2022 Retrieved 30 March 2020 Consensus document on the epidemiology of severe acute respiratory syndrome SARS Department of Communicable Disease Surveillance and Response Technical report World Health Organization p 26 hdl 10665 70863 WHO CDS CSR GAR 2003 11 A number of researchers have estimated the basic reproduction number by fitting models to the initial growth of epidemics in a number of countries Their observations indicate that the SARS CoV is less transmissible than initially thought with estimates of Ro in the range of 2 4 Gani R Leach S December 2001 Transmission potential of smallpox in contemporary populations Nature 414 6865 748 51 Bibcode 2001Natur 414 748G doi 10 1038 414748a PMID 11742399 S2CID 52799168 Retrieved 18 March 2020 Ireland s Health Services Health Care Worker Information PDF Retrieved 27 March 2020 Brown Catherine M 2021 Outbreak of SARS CoV 2 Infections Including COVID 19 Vaccine Breakthrough Infections Associated with Large Public Gatherings Barnstable County Massachusetts July 2021 MMWR Morbidity and Mortality Weekly Report 70 31 1059 1062 doi 10 15585 mmwr mm7031e2 ISSN 0149 2195 PMC 8367314 PMID 34351882 Lu Jing 7 July 2021 Viral infection and transmission in a large well traced outbreak caused by the Delta SARS CoV 2 variant virological org Archived from the original on 22 July 2021 Why The Delta Variant Is Hyper Contagious A New Study Sheds Light NPR 21 July 2021 Haseltine William A 13 July 2021 The Delta Dilemma Loosening Covid 19 Controls At A Time Of Increased Danger Forbes CDC covid variant tracker 28 March 2020 Retrieved 13 July 2021 RIVM Covid variant tracker Retrieved 13 July 2021 RKI Coronavirus SARS CoV 2 Berichte zu Virusvarianten von SARS CoV 2 in Deutschland www rki de Retrieved 19 June 2021 Cave Damien 2 July 2021 Why the Delta Variant Could End Australia s Pursuit of Covid Zero The New York Times Retrieved 9 July 2021 Demony Catarina 26 June 2021 Delta variant spreading rapidly from Lisbon to rest of Portugal Reuters Retrieved 28 June 2021 COVID 19 Russia battles Delta variant in deadly 3rd wave video Deutsche Welle 8 July 2021 Archived from the original on 9 July 2021 Retrieved 9 July 2021 Lawler Dave 8 July 2021 Indonesia s surging death rate underscores danger of Delta variant Axios Retrieved 16 July 2021 Delta Variante dominiert in Deutschland www aerzteblatt de in German 8 July 2021 Retrieved 9 July 2021 14 to 20 June Delta variant dominates cases in Luxembourg with 59 4 percent today rtl lu Retrieved 3 July 2021 From UK to Indonesia How Delta variant is dominating global Covid surge The Times of India 8 July 2021 Retrieved 16 July 2021 Delta variant rapidly advancing in Netherlands Possibly caused 50 of infections NL Times Retrieved 3 July 2021 Risikovurdering af B 1 617 2 opdatering PDF 2 July 2021 Delta variant to account for most new French COVID cases from this weekend minister Reuters 9 July 2021 Retrieved 9 July 2021 WHO Director General s opening remarks at the 8th meeting of the IHR Emergency Committee on COVID 19 14 July 2021 WHO 14 July 2021 Archived from the original on 15 July 2021 The Delta variant is now in more than 111 countries and we expect it to soon be the dominant COVID 19 strain circulating worldwide if it isn t already Corona antistoffen bij 93 van donors Sanquin Netherlands in Dutch Retrieved 29 July 2021 Antistoffen bij 95 van donors Sanquin in Dutch Retrieved 30 October 2021 Most Blood Donations Contain COVID 19 Antibodies www precisionvaccinations com Retrieved 30 October 2021 Coronavirus COVID 19 latest insights Office for National Statistics www ons gov uk Retrieved 30 October 2021 COVID 19 vaccine surveillance report Week 43 PDF Reardon Sara 21 July 2021 How the Delta variant achieves its ultrafast spread Nature doi 10 1038 d41586 021 01986 w Retrieved 13 August 2021 Li Baisheng et al 23 July 2021 Viral infection and transmission in a large well traced outbreak caused by the SARS CoV 2 Delta variant medRxiv 10 1101 2021 07 07 21260122v2 Subbaraman Nidhi 12 August 2021 How do vaccinated people spread Delta What the science says Nature 596 7872 327 328 Bibcode 2021Natur 596 327S doi 10 1038 d41586 021 02187 1 PMID 34385613 S2CID 236997139 Dey Sushmi Covid second wave in India Percentage of young infected in second wave same but more serious The Times of India Retrieved 27 April 2021 Delta Variant What We Know About the Science by Centers for Disease Control and Prevention Ong Sean Wei Xiang Chiew Calvin J Ang Li Wei Mak Tze Minn Cui Lin Toh Matthias Paul HS Lim Yi Ding Lee Pei Hua Lee Tau Hong Chia Po Ying Maurer Stroh Sebastian Lin Raymond Tzer Pin Leo Yee Sin Lee Vernon J Lye David Chien Young Barnaby E 7 June 2021 Clinical and Virological Features of SARS CoV 2 Variants of Concern A Retrospective Cohort Study Comparing B 1 1 7 Alpha B 1 315 Beta and B 1 617 2 Delta SSRN 3861566 Public Health England 11 June 2021 SARS CoV 2 variants of concern and variants under investigation in England Technical briefing 15 PDF gov uk p 50 Retrieved 22 July 2021 Twohig Katherine A Nyberg Tommy Zaidi Asad Thelwall Simon Sinnathamby Mary A Aliabadi Shirin Seaman Shaun R Harris Ross J Hope Russell Lopez Bernal Jamie Gallagher Eileen 27 August 2021 Hospital admission and emergency care attendance risk for SARS CoV 2 delta B 1 617 2 compared with alpha B 1 1 7 variants of concern a cohort study The Lancet Infectious Diseases 22 1 35 42 doi 10 1016 S1473 3099 21 00475 8 ISSN 1473 3099 PMC 8397301 PMID 34461056 Sheikh Aziz McMenamin Jim Taylor Bob Robertson Chris 2021 SARS CoV 2 Delta VOC in Scotland demographics risk of hospital admission and vaccine effectiveness The Lancet 397 10293 2461 2462 doi 10 1016 S0140 6736 21 01358 1 ISSN 0140 6736 PMC 8201647 PMID 34139198 Fisman David Tuite Ashleigh 12 July 2021 Progressive Increase in Virulence of Novel SARS CoV 2 Variants in Ontario Canada medRxiv 10 1101 2021 07 05 21260050v2 SARS CoV 2 variants of concern and variants under investigation in England PDF assets publishing service gov uk Public Health England Technical Briefing 18 9 July 2021 pp 10 11 Table 3 and footnote 2 of that table Retrieved 19 July 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 Kertscher Tom 7 July 2021 Data showing lower death rate for coronavirus delta variant doesn t mean it s less dangerous Politifact Retrieved 20 July 2021 Fisman David N Tuite Ashleigh R 4 October 2021 Evaluation of the relative virulence of novel SARS CoV 2 variants a retrospective cohort study in Ontario Canada Canadian Medical Association Journal 193 42 211248 doi 10 1503 cmaj 211248 ISSN 1488 2329 PMC 8562985 PMID 34610919 Canadian Study Reveals Delta Lethality Higher than Original COVID October 6 2021 Daily News Brief 6 October 2021 Retrieved 6 October 2021 Berger Miriam 28 November 2021 South Africa which found the omicron variant first leads Africa in coronavirus sequencing Washington Post Retrieved 2 December 2021 Sequencing by country GISAID 2 December 2021 Archived from the original on 2 December 2021 Retrieved 2 December 2021 a b c Tracking of Variants gisaid org GISAID 26 April 2021 Retrieved 23 November 2021 Weekly epidemiological update on COVID 19 11 May 2021 World Health Organization 11 May 2021 Retrieved 27 July 2021 Weekly epidemiological update on COVID 19 22 June 2021 www who int Retrieved 29 June 2021 PANGO lineages Lineage B 1 617 2 cov lineages org Retrieved 19 December 2021 COVID 19 variants genomically confirmed case numbers Gov uk Retrieved 19 December 2021 Variant Proportions Cdc gov 28 March 2020 Retrieved 30 July 2021 Tracking variants of the novel coronavirus in Canada Ctvnews ca 4 February 2021 Retrieved 19 December 2021 Infectious Diseases Weekly Report National Institute of Infectious Diseases Retrieved 30 July 2021 都道府県別の懸念される変異株の国内事例数 ゲノム解析 について Ministry of Health Labour and Welfare Retrieved 30 July 2021 Coronavirus live news 16 54 28 April 2021 The Guardian 28 April 2021 Retrieved 28 April 2021 The index case of the second wave was determined to be the Delta variant There have been over 47 000 cases originating from the index case Fiji Ministry of Health and Medical Services COVID 19 Cases Retrieved 5 September 2021 Fiji COVID 19 update for 10 July 2021 Fiji Village News 10 July 2021 Retrieved 10 July 2021 Fiji is racing against time to vaccinate its population while a COVID 19 outbreak explodes ABC News 10 July 2021 Retrieved 11 July 2021 Variants of Concern Communicable Disease Genomes Network Retrieved 5 December 2021 SP identifica primeiro caso de variante do coronavirus em passageiro vindo da India 26 05 2021 g1 globo com accessed 26 May 2021 Covid 19 Maranhao registra primeiros casos da variante indiana 21 May 2021 pebmed com br accessed 26 May 2021 Barbosa Alex 24 May 2021 Identificacao da variante indiana do coronavirus coincide com aumento de internacoes no Maranhao g1 globo com in Brazilian Portuguese TV Mirante e G1 MA Coronavirus Primeiro caso da variante indiana e confirmado no Parana diz Sesa tr Coronavirus First case of the Indian variant is confirmed in Parana says Sesa 02 06 2021 g1 globo com accessed 3 June 2021 Variante delta do coronavirus e identificada e tem transmissao comunitaria em Goiania g1 globo com accessed 23 June 2021 Casos da variante Delta podem estar subnotificados no Brasil Delta Brasil supera mil casos confirmados da variante crescimento foi de 84 em uma semana Saude Soni Parul 30 April 2021 Israel Is The Most Vaccinated Country But The B 1 617 Is Threatening It Now International Business Times IBT Media Israel logs Indian COVID 19 variant sees some vaccine efficacy against it Reuters 20 April 2021 Retrieved 24 April 2021 זוהו 41 מקרים של הזן הווריאנט ההודי מתוכם 24 חוזרים מחו ל 41 cases of the Indian variety have been identified of which 24 are from abroad GOV IL in Hebrew Retrieved 29 April 2021 Indisk virusvariant pavist i Norge Indian virus variant detected in Norway dagbladet no 16 April 2021 Retrieved 28 April 2021 Update On Covid 19 08th May 2021 SA Corona Virus Online Portal SA Corona Virus Online Portal Retrieved 10 May 2021 Minister zdrowia mamy kolejne dwa ogniska zwiazane z mutacja indyjska koronawirusa Health Minister We have two more outbreaks related to the Indian mutation of the coronavirus tvn24 pl in Polish 4 May 2021 Retrieved 4 May 2021 Lithuania detects first case of coronavirus Delta variant from India lrt lt en news in english 17 June 2021 Retrieved 17 June 2021 a b Indian Covid variant reaches Finland YLE Finland 29 April 2021 Retrieved 13 May 2021 Intialaiseen muunnokseen on sairastunut Suomessa kymmenkunta henkea Uudenmaan koronaviruskanta on vaihtunut taysin alkuvuoden aikana About a dozen people in Finland have contracted the Indian variant the coronavirus variants seen in Uusimaa have completely changed in the first part of the year yle fi in Finnish 10 May 2021 Retrieved 17 May 2021 Virologist Indian variant not major concern in Finland though care should be taken Yle Finland 27 May 2021 Retrieved 27 May 2021 Situation update on coronavirus Coronavirus variants Finnish Institute for Health and Welfare 11 August 2021 Retrieved 11 August 2021 Delta variant 2 876 de Vera Analou 9 December 2021 DOH No Omicron variant yet in PH Manila Bulletin Retrieved 10 December 2021 Philippines detects 492 new Omicron cases total at 535 GMA News 19 January 2022 Retrieved 24 January 2022 Russia records first cases of COVID variant found in India The Economic Times Retrieved 13 May 2021 Indian variant of Covid 19 confirmed in Thailand Bangkok Post 10 May 2021 Retrieved 11 May 2021 Osborne Samuel 23 August 2021 COVID 19 New Zealand extends coronavirus lockdown amid Delta variant outbreak Sky News Retrieved 23 August 2021 New Zealand reported 35 new cases of COVID 19 bringing the number of current infections to 107 Clark Emily 22 August 2021 New Zealand COVID 19 outbreak grows strict lockdown extended abc net au Retrieved 23 August 2021 The strict level 4 lockdown across New Zealand has been extended as the country s Delta outbreak climbs to more than 100 cases a b c Nigeria Algeria report Indian variant of the coronavirus WHO says without further details africanews com 13 May 2021 Retrieved 14 May 2021 Covid Indian Variant Detected In Kenya ndtv com 5 May 2021 Retrieved 7 May 2021 Vietnam detects double mutant Indian variant of coronavirus for 1st time tuoitrenews vn 2 May 2021 Retrieved 17 May 2021 Indian coronavirus variant found in COVID 19 cases linked to National Hospital for Tropical Diseases vietnamnews vn 11 May 2021 Retrieved 17 May 2021 IEDCR Indian Covid variant found in six Bangladeshis Dhaka Tribune 17 May 2021 Retrieved 18 May 2021 যশ র আর ৩জন র শর র কর ন র ভ রত য ভ য র য ন ট শন ক ত Indian variant of coronavirus identified in 3 more people in Jessore District Youtube Jamuna TV 18 May 2021 Retrieved 18 May 2021 Covid 19 Indian variant spreads to neighbouring countries detected in Sri Lanka Bangladesh Times of India 8 May 2021 Retrieved 11 May 2021 Botswana confirms new COVID 19 variant Weekend Post 17 May 2021 Retrieved 18 May 2021 Cases of South African and Indian coronavirus strains detected in Argentina MercoPress 11 May 2021 Retrieved 11 May 2021 Raising fears of COVID surge Uganda detects Indian variant official says Reuters 30 April 2021 Retrieved 8 May 2021 Nepal reports more Covid 19 deaths and record daily new infections Kathmandu Post 11 May 2021 Retrieved 11 May 2021 Yabiladi com Morocco Two cases of the Indian variant of Covid 19 confirmed in Casablanca en yabiladi com in French Retrieved 3 May 2021 a b c d Weekly epidemiological update on COVID 19 18 May 2021 World Health Organization 18 May 2021 Retrieved 19 May 2021 Lamb Kate 10 August 2021 East Timor detects first domestic transmission of COVID 19 Delta variant Reuters Retrieved 13 August 2021 Algeria finds first cases of Indian coronavirus variant Reuters 4 May 2021 Retrieved 14 May 2021 Iran reports three cases of Indian coronavirus variant Al Arabiya 5 May 2021 Retrieved 14 May 2021 Coronavirus New Variants Confirmed in 15 New Cases Hungary Today 22 July 2021 Retrieved 28 August 2021 Tests by the National Public Health Centre NNK showed the presence of the Delta variant of the coronavirus in 14 new cases and the gamma variant in one new case the prime minister s chief of staff said on Thursday Cyprus finds first cases of Indian COVID variant Reuters 19 May 2021 Retrieved 19 May 2021 First case of Indian variant detected at Tocumen International ndtv com 8 May 2021 Retrieved 14 May 2021 PANGO lineages Lineage B 1 617 cov lineages org Retrieved 26 May 2021 SARS CoV 2 variants of concern and variants under investigation in England Technical briefing 10 PDF Report London Public Health England 7 May 2021 Retrieved 7 May 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 British scientists warn over Indian coronavirus variant Reuters 7 May 2021 Retrieved 7 May 2021 Davis Nicola 7 May 2021 Indian Covid variant is of concern says Public Health England The Guardian London Retrieved 7 May 2021 Confirmed cases of COVID 19 variants identified in UK www gov uk 3 June 2021 Retrieved 3 June 2021 nbsp This article incorporates text published under the British Open Government Licence v3 0 Confirmed cases of COVID 19 variants identified in UK www gov uk 11 June 2021 Archived from the original on 11 June 2021 Retrieved 11 June 2021 span data sr, 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.