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 included (last update: 2022-06-10)
- Forest plots - RNA based vaccine (last update: 2021-12-02)
- Forest plots - Non replicating viral vector (last update: 2021-12-02)
- Forest plots - Inactivated virus (last update: 2021-12-02)
- Forest plots - Any vaccine (last update: 2021-12-02)
- Forest plots - Booster (last update: 2021-11-26)
- Studies included (last update: 2021-12-13)
- Forest plots - RNA based vaccine (last update: 2021-11-12)
- Forest plots - Non replicating viral vector (last update: 2021-11-12)
- Forest plots - Any vaccine (last update: 2021-11-05)
- Studies included (last update: 2021-10-27)
- Forest plots - RNA based vaccine (last update: 2021-10-28)
- Forest plots - Inactivated virus (last update: 2021-10-14)
- Studies included (last update: 2021-11-15)
- Forest plots - RNA based vaccine (last update: 2021-10-21)
- Studies included (last update: 2024-04-27)
- Forest plots - RNA based vaccine (last update: 2021-10-21)
- Forest plots - Non replicating viral vector (last update: 2021-10-21)
Delta
Alpha
Gamma
Beta
Beta-gamma
Studies for variant alpha
| Trial | Design | Variant | Participants | Comparisons | ||||
|---|---|---|---|---|---|---|---|---|
| Type | Intervention 1 | Intervention 2 | Overall risk of bias Highest assessment |
Full description | ||||
|
Amirthalingam G, medRxiv, 2021 Full text Commentary Commentary |
Test-negative | Alpha | Healthy adults aged 50-64 years in England | Non replicating viral vector | ChAdOx1-S | No vaccine | Extraction in progress | |
| RNA based vaccine | BNT162b2 | No vaccine | Extraction in progress | |||||
|
NCT04607941 Charmet T, Lancet Reg Health Eu, 2021 Full text 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 |
|
|
Chemaitelly H, Nat. Med., 2021 Full text |
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 |
|
|
Chemaitelly H, N Eng J Med, 2021 Full text Commentary |
Test-negative | Alpha | Adults and children with PCR-confirmed/negative SARS-CoV-2 in Qatar. | RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|
|
Chung H, BMJ, 2021 Full text Commentary Commentary Commentary |
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 |
|
|
Corchado-Garcia J, medRxiv, 2021 Full text Commentary |
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 |
|
|
Dagan N, Nat Med, 2021 Full text Commentary |
Cohort | Alpha | Pregnant women, aged 16 years or older, in Israel | RNA based vaccine | BNT162b2 | No vaccine |
Moderate Details |
|
|
Dagan N, N Engl J Med, 2021 Full text 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 |
|
|
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 |
|
| 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 Full text 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 |
|
|
Glampson B, medRxiv, 2021 Full text 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 |
|
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|||||
|
Goldshtein I, JAMA, 2021 Full text Commentary Commentary |
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 |
|
|
Haas E, Lancet, 2021 Full text Commentary |
Cohort | Alpha | Adults (16 years and older) with no history of COVID-19 in Israel | RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|
|
ISRCTN, number 39557. Hyams C, Lancet Infect Dis, 2021 Full text 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 |
|
| RNA based vaccine | BNT162b2 | No vaccine |
Moderate Details |
|||||
|
Kim S, J Infect Dis, 2021 Full text 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 |
|
|
Layan M, medRxiv, 2021 Full text |
Cohort | Alpha | Household members close contact of an HCW index case | RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|
|
Lopez Bernal J, BMJ, 2021 Full text Commentary Commentary |
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 |
|
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|||||
|
Lopez J, N Engl J Med, 2021 Full text Commentary |
Test-negative | Alpha | Data on all symptomatic sequenced cases of COVID-19 in England | Non replicating viral vector | ChAdOx1-S | No vaccine |
Serious Details |
|
| Any COVID-19 vaccine | BNT162b2 or ChAdOx1-S | No vaccine |
Serious Details |
|||||
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
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|
Lumley S, Clin Infect Dis, 2021 Full text Commentary Commentary |
Cohort | Alpha | Staff at 4 hospitals and associated facilities in Oxfordshire, UK. | Any COVID-19 vaccine | BNT162b2 or ChAdOx1 | No vaccine |
Serious Details |
|
|
McKeigue P, medRxiv, 2021 Full text Commentary Commentary |
Case-control | Alpha | Population of Scotland | Any COVID-19 vaccine | BNT162b2 or mRNA-1273 or ChAdOx1-S | No vaccine |
Serious Details |
|
|
Nasreen S, medRxiv, 2021 Full text Full text Commentary Commentary |
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 |
|
| Non replicating viral vector | ChAdOx1-S | No vaccine |
Serious Details |
|||||
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|||||
|
Pilishvili T, NEJM, 2021 Full text Commentary |
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 |
|
| RNA based vaccine | BNT162b2 | No vaccine |
Moderate Details |
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|
ISRCTN21086382 Pouwels K, Nat Med, 2021 Full text Full text Commentary Commentary |
Cohort | Alpha | Adults from households randomly selected across the UK. | RNA based vaccine | mRNA-1273 | No vaccine |
Moderate Details |
|
| Non replicating viral vector | ChAdOx1-S | No vaccine |
Moderate Details |
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| RNA based vaccine | BNT162b2 | No vaccine | Extraction in progress | |||||
|
Puranik A, medRxiv, 2021 Full text Commentary Commentary |
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 |
|
| RNA based vaccine | mRNA-1273 | BNT162b2 |
Serious Details |
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| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
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|
Regev-Yochay G, Lancet Reg Health, 2021 Full text |
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 |
|
|
Seppala E, Euro Surveill, 2021 Full text Commentary |
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 |
|
|
Sheikh A, Lancet, 2021 Full text Commentary |
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 |
|
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
|||||
|
Skowronski D, Clin Infect Dis, 2021 Full text Commentary Commentary |
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 |
|
|
Tenforde M, Clin Infect Dis, 2021 Full text Commentary Commentary |
Test-negative | Alpha | Hospitalized adults at 18 centers in the USA. | RNA based vaccine | mRNA-1273 | No vaccine |
Serious Details |
|
| RNA based vaccine | BNT162b2 or mRNA-1273 | No vaccine |
Serious Details |
|||||
| RNA based vaccine | BNT162b2 | No vaccine |
Serious Details |
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|
Tenforde M, MMWR, 2021 Full text Commentary |
Cohort | Alpha | Hospitalized adults at 21 centers in the USA | RNA based vaccine | mRNA-1273 | No vaccine | Extraction in progress | |
| 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 Full text Commentary Commentary Commentary |
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 |
|
| 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 |
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