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Living Evidence - SARS-CoV-2 variants

Living evidence tables provide high level summaries of key studies and evidence on a particular topic, and links to sources. They are reviewed daily and updated as new evidence and information is published.

Viruses constantly change through mutation and over time, new variants of a virus are expected to occur. Some variants have characteristics that have a significant impact on transmissibility, severity of disease and effectiveness of vaccines.  This table includes information on variants that are currently causing concern in the scientific community.

Currently there are three variants of concern – all have the N501Y mutation - a change from asparagine (N) to tyrosine (Y) at amino-acid site 501.

 B.1.1.7B.1.351 B.1.1.28.1 (P.1 and P.2)
Alternate names 501Y.V1
Variant of Concern (VOC)-202012/01
Kent
501Y.V2 501Y.V3
First detected UK, September 2020 South Africa, December 2020 Brazil, December 2020
Mutations 23 (17 of which change amino acids) 21 17 (11 of which change amino acids)
Transmissibility compared with wild type

An estimated 43–90% higher reproduction number than pre-existing variants.

50% increase Not established
Virulence / severity or duration of disease compared with wild type

Reports of 35% increased mortality.*

Preprint data reports B.1.1.7 infections last 13.3 days compared with 8.2 days for other variants*^

Reports of severe reinfection* however no data to suggest increased mortality^Not established
Immune escape (vaccines / previous infections will not be protective)

Reports of 74.6% efficacy for Astra-Zeneca.*^

Reports of 86% efficacy for Novavax vaccine.*^

Multiple studies show effective at neutralizing B.1.1.7 for Pfizer/BioNTech*^

No significant impact on neutralization for Moderna.*^

Preprint data reports 10.4% efficacy against mild to moderate disease for Astra-Zeneca vaccine.*^

Reports of 50-60% efficacy for Novavax vaccine.*^

Preprint data reports a 3.5-fold reduction in neutralizing antibody titers; however most individuals neutralize the SARS-CoV-2 B.1.351 variant suggesting that protective immunity is retained for Moderna.*

Reductions by a factor of 6.4 in titers of neutralizing antibodies for Moderna.*^

Reports of 85% efficacy for the Ad26COVs.S (Johnson & Johnson) vaccine*^

Reduction in neutralization by approximately two thirds for Pfizer/BioNTech.*^

Reports of vaccine booster to target variant for Pfizer/BioNTech.^

T cell responses in COVID-19 mRNA vaccines are not substantially affected by mutations found in the SARS-CoV-2 variants.^

Reports of reinfection*

Significant reduction in neutralization in fully vaccinated individuals for Pfizer/BioNTech and Moderna.*^

T cell responses in COVID-19 mRNA vaccines are not substantially affected by mutations found in the SARS-CoV-2 variants.^

Rapid antigen test sensitivity

Not affected*

Preprint data reports on two variant-specific RT-PCR tests which detect fraction of infections caused by B.1.1.7, B.153, and P.1*

Preprint developed and validated RT-qPCR method for detection of B.1.1.7 and B.1.351 shown to be sensitive and specific,^ and another specific to B.1.1.7.^

Preprint data reports on two variant-specific RT-PCR tests which detect fraction of infections caused by B.1.1.7, B.153, and P.1*

Preprint developed and validated RT-qPCR method for detection of B.1.1.7 and B.1.351 shown to be sensitive and specific.^

Preprint data reports on two variant-specific RT-PCR tests which detect fraction of infections caused by B.1.1.7, B.153, and P.1*
Links with post-acute COVID-19 syndrome Not established Not established Not established
Countries reporting detection (not necessarily local transmission)Detected in 93 countries

Dominant strain in UK
Detected in 46 countries

Dominant strain in South Africa
Detected in 22 countries

Key variants of concern are added to the table when they meet the World Health Organisation definition of variants of interest and variants of concern.

Reports in the press

Preprint report on the emergency of a 484K variant in the B.1.526 linkage in New York

News reporting a mutation of B.1.1.7 and CAL.20C^

new variant (B.1.2/20G clade) “Robin” in October 2020; now detected in 30 states in the US.

new variant (B1525) identified in the UK with sequences dated to December 2020, now detected in 13 countries.

new variant (CAL.20C) identified in Southern California in July 2020; now detected in 26 states in the US and other countries. The variant spans the B.1.427 and B.1.429 lineages. There is no indication this is a more transmissible variant.

A new variant (A.23.1) identified in Uganda; the clinical impact is not established.

Notes

*Preliminary data, not fully established, in some cases small numbers or short follow up; interpret with caution

^ Commentary grey literature, pre peer review or news

Background

Evidence check - SARS-CoV-2 variants (PDF)

Living evidence tables include some links to low quality sources and an assessment of the original source has not been undertaken. Sources are monitored daily but due to rapidly emerging information, tables may not always reflect the most current evidence. The tables are not peer reviewed, and inclusion does not imply official recommendation nor endorsement of NSW Health.

Last updated on 4 Mar 2021

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