COVID-19 vaccine effectiveness
(Randomized evidence)

Trial Type Comparisons Design Participants Sample size Overall risk
of bias
Highest assessment
Full description
Intervention 1 Intervention 2
NCT04683484
Nanogen Pharmaceutical Biotechnology JSC
Nguyen T, SSRN, 2021

Full text
Full text
Commentary
Commentary
Protein subunit

Nanocovax 25 mcg

Nanocovax 50 mcg

Nanocovax 75 mcg

RCT
Phase 1
Healthy HIV-negative and seronegative adults at a single center in Vietnam N=60
Some concerns
Details

Full description

NCT04400838
AstraZeneca + University of Oxford
Voysey M, Lancet, 2020
COV002

Full text
Commentary
Non replicating viral vector

ChAdOx1 LD/SD

ChAdOx1 SD/SD

Placebo

RCT
Phase 2/3
Healthy adults in 18 centres in the UK N=10673
Some concerns
Details

Full description

ISRCTN89951424
AstraZeneca + University of Oxford
Voysey M, Lancet, 2020
COV003

Full text
Commentary
Non replicating viral vector

ChAdOx1

Placebo

RCT
Phase 3
Healthy SARS-CoV-2 serology/DNA negative adults in six centres in Brazil N=10002
Some concerns
Details

Full description