COVID-19 vaccine effectiveness on variants of concern
(Randomized evidence)

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Alpha

Forest plots
(last update: 2021-07-27)

Description of primary studies

Trial Type Comparisons Design Participants Sample size Overall risk
of bias
Highest assessment
Full description
Intervention 1 Intervention 2
Alpha
Delta
NCT04641481
Bharat Biotech
Ella R, medRxiv, 2021
New

Full text
Commentary
Commentary
Inactivated virus

BBV152

Placebo

RCT
3
Adults with no history of SARS-CoV-2 infection who were healthy or had stable chronic medical conditions at 25 centers in India N=25778
Some concerns
Details

Full description

Alpha
NCT04400838
AstraZeneca + University of Oxford
Emary K, Lancet, 2021

Full text
Commentary
Non replicating viral vector

ChAdOx1

MenACWY

RCT
Phase 2-3
Adults seronegative at baseline enrolled at 19 study sites in UK N=10673
Some concerns
Details

Full description

Alpha
NCT04583995; EudraCT 2020-004123-16
Novavax
Heath P, N Engl J Med, 2021

Full text
Commentary
Protein subunit

NVX-CoV2373

Placebo

RCT
Phase 3
Adults 18 to 84 years old who were healthy or had stable chronic medical conditions with no history of COVID-19 at 33 centres in the UK. N=15187
Some concerns
Details

Full description