COVID-19 vaccine effectiveness
(Randomized evidence)



Results of booster studies are available in the tables below and are updated on a monthly basis.

As of December 14, 2022, the COVID-NMA revised its protocol and discontinued the inclusion of prime vaccination trials in its analysis. The analysis presented on this page for prime vaccines compared to placebo or other vaccines includes trials that were identified and included up to December 14, 2022. A list of studies that were eligible up to this date but not extracted is provided in detail here .

On December 7, 2022, we published results of the systematic review "Efficacy and safety of COVID‐19 vaccines" which included 41 preprints and published trials of 12 different COVID-19 used as prime vaccination and that were published before 5 November 2021.


Perform your own analysis using COVID-NMA data for prime vaccination (last search date 14/12/2022), create and download your forest plots by clicking below:

go to metacovid

Vaccine types


Vaccine efficacy, immunogenicity and safety of booster vs no booster (tables)

Vaccine efficacy, immunogenicity and safety of booster VS booster (tables)

COVID-19 PRIME VACCINATION: Last search date December 14, 2022.

Vaccine efficacy and safety for vaccine vs placebo / no vaccine (forest plots)

Vaccine efficacy and safety for vaccine vs vaccine (forest plots)

Vaccine efficacy, immunogenicity and safety of heterologous vs homologous vaccination (tables)

Vaccine efficacy and safety against variants of concern (forest plots)

Search studies

Search by Vaccine name Author Registration number
Trial Type Comparisons Design Participants Sample size Overall risk
of bias
Highest assessment
Full description
Intervention 1 Intervention 2
Medicago Inc
Hager K, N Engl J Med, 2022

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Virus-Like particle

CoVLP 3.75mcg +AS03 D0/21


Phase 3
Adults including elderly with and without comorbidities, with no previous history of virologically confirmed COVID-19, both seronegative and seropositive, at 85 centers in Argentina, Brazil, Canada, Mexico, the UK, and the USA. N= 24141
Some concerns

Full description