COVID-19 vaccine effectiveness on variants of concern

Observational studies

Protocol

Our protocol is available on Zenodo here .

Last search data: Nov 3, 2021.

The project stopped after this date and the analysis presented include eligible studies up to Nov 3, 2021.

Variants of concern

We identified observational studies assessing vaccine effectiveness on variant from the studies identified by Krause P et al. Lancet 2021 and the process described in our protocol .

Vaccine effectiveness is based on direct evidence but also indirect evidence (i.e., variant exposure extrapolated the prevalence of the variant in the population) reported in the manuscript or in secondary sources.

Risk of bias assessment is ongoing and may be missing on the forest plots.

Studies for variant alpha

See all studies

Trial Design Variant Participants Comparisons
Type Intervention 1 Intervention 2 Overall risk
of bias
Highest assessment
Full description


Amirthalingam G, medRxiv, 2021

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Commentary
Commentary
Test-negative Alpha Healthy adults aged 50-64 years in England Non replicating viral vector ChAdOx1-S No vaccine Extraction in progress

Full description

RNA based vaccine BNT162b2 No vaccine Extraction in progress
NCT04607941

Charmet T, Lancet Reg Health Eu, 2021

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Commentary
Case-control Alpha Adults in France with or without prior history of infection (>2 months previous to index infection) RNA based vaccine BNT162b2 No vaccine
Serious
Details

Full description



Chemaitelly H, N Eng J Med, 2021

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Commentary
Test-negative Alpha Adults and children with PCR-confirmed/negative SARS-CoV-2 in Qatar. RNA based vaccine BNT162b2 No vaccine
Serious
Details

Full description



Chemaitelly H, Nat. Med., 2021

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Test-negative Alpha Mainly working-age adults not vaccinated or receiving at least one dose of the mRNA- 1273 vaccine or completed the two-dose regimen RNA based vaccine mRNA-1273 No vaccine
Serious
Details

Full description



Chung H, BMJ, 2021

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Commentary
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Test-negative Alpha People with COVID-like symptoms and with no history of COVID-19 tested for SARS-CoV-2 RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Moderate
Details

Full description



Corchado-Garcia J, medRxiv, 2021

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Cohort Alpha Adults who underwent SARS-CoV-2 polymerase chain reaction (PCR) testing in multiple centers in USA Non replicating viral vector Ad26.COV2.S No vaccine
Serious
Details

Full description



Dagan N, N Engl J Med, 2021

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Commentary
Cohort Alpha Individuals 16 years and older with no previous documented infection with SARS-CoV-2 (PCR) in Israel RNA based vaccine BNT162b2 No vaccine
Moderate
Details

Full description



Dagan N, Nat Med, 2021

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Commentary
Cohort Alpha Pregnant women, aged 16 years or older, in Israel RNA based vaccine BNT162b2 No vaccine
Moderate
Details

Full description



Flacco M, Vaccines, 2021

mdpi.com/2076-393X/9/6/628Commentary
Cohort Alpha Adults aged 18 and up without previous SARS-CoV-2 infection residing in Pescara, Italy RNA based vaccine mRNA-1273 No vaccine
Serious
Details

Full description

Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details
Any COVID-19 vaccine BNT162b2 or mRNA-1273 or ChAdOx1-S No vaccine
Serious
Details
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Giansante C, Acta Biomed, 2021

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Commentary
Cohort Alpha The staff of the Bologna Health Trust, Emilia Romagna Region, Northern Italy. RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Serious
Details

Full description



Glampson B, medRxiv, 2021

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Commentary
Cohort Alpha Adults (16 years and older) eligible to be offered a COVID-19 in the UK. Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details

Full description

RNA based vaccine BNT162b2 No vaccine
Serious
Details


Goldshtein I, JAMA, 2021

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Cohort Alpha Pregnant women with no history of SARS-CoV-2 registered in a a large state-mandated health care organization in Israel RNA based vaccine BNT162b2 No vaccine
Moderate
Details

Full description



Haas E, Lancet, 2021

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Cohort Alpha Adults (16 years and older) with no history of COVID-19 in Israel RNA based vaccine BNT162b2 No vaccine
Serious
Details

Full description

ISRCTN, number 39557.

Hyams C, Lancet Infect Dis, 2021

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Commentary
Test-negative Alpha Adults >80 years who were admitted to hospital in two NHS trusts in Bristol, UK with signs and symptoms of respiratory disease(test-positive/negative) Non replicating viral vector ChAdOx1-S No vaccine
Moderate
Details

Full description

RNA based vaccine BNT162b2 No vaccine
Moderate
Details


Kim S, J Infect Dis, 2021

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Commentary
Test-negative Alpha Adolescents and adults with COVID-like symptoms at 5 centers in the USA. RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Serious
Details

Full description



Layan M, medRxiv, 2021

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Cohort Alpha Household members close contact of an HCW index case RNA based vaccine BNT162b2 No vaccine
Serious
Details

Full description



Lopez Bernal J, BMJ, 2021

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Test-negative Alpha Adults aged 70 years and older who reported symptoms of COVID-19 Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details

Full description

RNA based vaccine BNT162b2 No vaccine
Serious
Details


Lopez J, N Engl J Med, 2021

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Test-negative Alpha Data on all symptomatic sequenced cases of COVID-19 in England Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details

Full description

Any COVID-19 vaccine BNT162b2 or ChAdOx1-S No vaccine
Serious
Details
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Lumley S, Clin Infect Dis, 2021

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Commentary
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Cohort Alpha Staff at 4 hospitals and associated facilities in Oxfordshire, UK. Any COVID-19 vaccine BNT162b2 or ChAdOx1 No vaccine
Serious
Details

Full description



McKeigue P, medRxiv, 2021

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Commentary
Case-control Alpha Population of Scotland Any COVID-19 vaccine BNT162b2 or mRNA-1273 or ChAdOx1-S No vaccine
Serious
Details

Full description



Nasreen S, medRxiv, 2021

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Commentary
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Test-negative Alpha Symptomatic community-dwelling individuals aged ≥16 years with no history of SARS-CoV-2 infection in Canada RNA based vaccine mRNA-1273 No vaccine
Serious
Details

Full description

Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Pilishvili T, NEJM, 2021

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Test-negative Alpha Health care personnel without previous SARS-CoV-2 infection at 33 centers in USA. RNA based vaccine mRNA-1273 No vaccine
Moderate
Details

Full description

RNA based vaccine BNT162b2 No vaccine
Moderate
Details
ISRCTN21086382

Pouwels K, Nat Med, 2021

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Cohort Alpha Adults from households randomly selected across the UK. RNA based vaccine mRNA-1273 No vaccine
Moderate
Details

Full description

Non replicating viral vector ChAdOx1-S No vaccine
Moderate
Details
RNA based vaccine BNT162b2 No vaccine Extraction in progress


Puranik A, medRxiv, 2021

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Cohort Alpha Adults who underwent SARS-CoV-2 polymerase chain reaction (PCR) testing at the Mayo Clinic and hospitals affiliated with the Mayo Clinic Health S RNA based vaccine mRNA-1273 No vaccine
Serious
Details

Full description

RNA based vaccine mRNA-1273 BNT162b2
Serious
Details
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Regev-Yochay G, Lancet Reg Health, 2021

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Cohort Alpha Health care workers who have had a possible or confirmed exposure to a SARS-CoV-2-infected person and/or have any COVID-19-associated symptom RNA based vaccine BNT162b2 No vaccine
Serious
Details

Full description



Seppala E, Euro Surveill, 2021

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Cohort Alpha All adults aged 18 years or older with no prior SARS-CoV-2 infection with a national identification number registered in multiple centres in Norway RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Serious
Details

Full description



Sheikh A, Lancet, 2021

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Test-negative Alpha People of all ages tested for COVID-19 by RT-PCR in Scotland Non replicating viral vector ChAdOx1-S No vaccine
Serious
Details

Full description

RNA based vaccine BNT162b2 No vaccine
Serious
Details


Skowronski D, Clin Infect Dis, 2021

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Test-negative Alpha Elderly aged 70 and older in communities in British Colombia, Canada RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Serious
Details

Full description



Tenforde M, Clin Infect Dis, 2021

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Test-negative Alpha Hospitalized adults at 18 centers in the USA. RNA based vaccine mRNA-1273 No vaccine
Serious
Details

Full description

RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Serious
Details
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Tenforde M, MMWR, 2021

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Cohort Alpha Hospitalized adults at 21 centers in the USA RNA based vaccine mRNA-1273 No vaccine Extraction in progress

Full description

RNA based vaccine BNT162b2 or mRNA-1273 No vaccine Extraction in progress
RNA based vaccine BNT162b2 No vaccine
Serious
Details


Thompson M, N Engl J Med, 2021

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Commentary
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Test-negative Alpha Adults ≥50 years with Covid-19–like illness at multiple sites in the USA RNA based vaccine mRNA-1273 No vaccine
Moderate
Details

Full description

RNA based vaccine BNT162b2 or mRNA-1273 No vaccine
Moderate
Details
RNA based vaccine BNT162b2 No vaccine
Moderate
Details
Non replicating viral vector Ad26.COV2.S No vaccine
Moderate
Details