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

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Alpha

Forest plots
(last update: 2022-04-15)

Description of primary studies

Trial Type Comparisons Design Participants Sample size Overall risk
of bias
Highest assessment
Full description
Intervention 1 Intervention 2
Alpha
Beta
Delta
NCT05033847
National Vaccine and Serum Institute, China; Sinopharm + China National Biotec Group Co + Beijing Institute of Biological Products
Al Kaabi N, Sig Transduct Target, 2022

Full text
Commentary
Heterologous booster

BBIBP-CorV/BoostNVSI 1-3m

BBIBP-CorV/Boost 1-3m

RCT
Phase 2
Healthy adults with no history of SARS-CoV-2 infection who had previously received a primary series (two doses) of BBIBP-CorV at a single center in United Arab Emirates N=1800
Some concerns
Details

Full description

Alpha
Gamma
Delta
NCT04646590
Anhui Zhifei Longcom Biopharmaceutical
Dai L, N Engl J Med, 2022

Full text
Commentary
Commentary
Protein subunit

ZF2001

Placebo

RCT
Phase 3
Adults 18 years of age or older with no history of Covid-19, positive tests for SARS-CoV-2 exposure or vaccination, or of congenital or acquired immune deficiency or autoimmune disease at 32 clinical centers across Uzbekistan, Indonesia, Pakistan, Ecuador and China. N=28904 Variant delta:

Some concerns
Details

Full description

Alpha
NCT04611802
Novavax
Dunkle L M, N Engl J Med, 2021

Full text
Commentary
Protein subunit

NVX-CoV2373

Placebo

RCT
Phase 3
Healthy adults in 113 sites in the USA and 6 in Mexico N=29949
Some concerns
Details

Full description

Alpha
Delta
NCT04641481
Bharat Biotech
Ella R, Lancet, 2021

Full text
Commentary
Inactivated virus

BBV152

Adjuvant

RCT
Phase 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=25798 Variant delta:

Some concerns
Details Variant alpha:

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 Variant alpha:

Some concerns
Details

Full description

Alpha
Beta
Gamma
Delta
NCT04636697
Medicago Inc
Hager K, N Engl J Med, 2022

Full text
Full text
Commentary
Virus-Like particle

CoVLP

Placebo

RCT
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 Variant delta:

Some concerns
Details

Full description

Alpha
NCT04526990
CanSino Biological Inc./Beijing Institute of Biotechnology
Halperin SA, Lancet, 2021

Full text
Commentary
Commentary
Non replicating viral vector

Ad5-nCoV

Adjuvant

RCT
Phase 3
Healthy adults with no history of laboratory-confirmed COVID-19 at 66 sites in Argentina, Chile, Mexico, Pakistan, and Russia N=36982
Some concerns
Details

Full description

Alpha
Beta
Gamma
Delta
NCT04614948
Janssen Pharmaceutical Companies
Hardt K, medRxiv, 2022
ENSEMBLE2

Full text
Commentary
Commentary
Non replicating viral vector

Ad26.COV2.S Ad26.COV2.S

Placebo

RCT
Phase 3
Adults, healthy or with stable and well-controlled comorbidities, at 125 centers in Belgium, Brazil, Colombia, France, Germany, The Philippines, South Africa, Spain, UK, and USA N=31835
Some concerns
Details

Full description

Alpha
NCT04614948
Janssen Pharmaceutical Companies
Hardt K, medRxiv, 2022
ENSEMBLE2

Full text
Commentary
Commentary
Non replicating viral vector

Ad26.COV2.S

Placebo

RCT
Phase 3
Adults, healthy or with stable and well-controlled comorbidities, at 125 centers in Belgium, Brazil, Colombia, France, Germany, The Philippines, South Africa, Spain, UK, and USA N=31835
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 Variant alpha:

Some concerns
Details

Full description

Alpha
Beta
Delta
NCT04649021
Pfizer/BioNTech+Fosun Pharma
Hui AH, SSRN, 2022

Full text
Commentary
Commentary
RNA based vaccine

BNT162b2

Placebo

RCT
Phase 2
Healthy adults and those with a pre-existing stable condition, at 2 centers in China. N=960
Low
Details

Full description

Alpha
Beta
Delta
NCT04900467; EudraCT: 2021-002174-52
Moderna;Pfizer/BioNTech
Janssen C, EClinicalMedicine, 2022

Full text
Full text
Commentary
Heterologous vaccination scheme

BNT/mRNA-1273

m1273/BNT162b2

BNT162b2

mRNA-1273

RCT
Phase 2
Adults with no known or suspected history of SARS-CoV-2 infection at 17 centers in France. N=414
Some concerns
Details

Full description

Alpha
Gamma
NCT04652102; EudraCT 2020-003998-22
CureVac AG
Kremsner P, Lancet Infect Dis, 2022
HERALD

Full text
Commentary
RNA based vaccine

CVnCoV

Placebo

RCT
Phase 2-3
Adults with no history of COVID-19 in 47 centers in Belgium, Germany, The Netherlands, Spain, Argentina, Colombia, Dominican Republic, Mexico, Panama and Peru N=39680
Some concerns
Details

Full description

Alpha
Beta
Delta
NCT04368988
Novavax
Mallory R, medRxiv, 2021

Full text
Commentary
Commentary
Protein subunit

NVX-CoV2373 boost

NVX-CoV2373

RCT
Phase 2
Healthy adults (stable comorbidities and confirmed COVID-19 with mild symptoms permitted) who had received 2 doses NVX-CoV2373 or placebo in a trial at 17 centers in Australia and USA N=383 N/A

Full description

Alpha
Delta
NCT04922788
Nanogen Pharmaceutical Biotechnology JSC.
Nguyen TP, medRxiv, 2022

Full text
Commentary
Commentary
Protein subunit

Nanocovax

Placebo

RCT
Phase 3
Healthy adult without previous or current SARS-CoV-2 infection in four centres in Vietnam. N=13007 Variant delta:

Some concerns
Details

Full description

Alpha
Beta
Gamma
Delta
NCT05142319
Pfizer/BioNTech+Fosun Pharma; ModernaTX
Poh XY, Clin. Infect. Dis., 2022
PRIBIVAC

Full text
Commentary
RNA based vaccine

BNT162b2/boostm1273

BNT162b2/boostBNT

RCT
3
Adults at a single center in Singapore with no previous history of COVID-19 who had received a primary series of BTN162b2 at least 6 months previously N=100
Some concerns
Details

Full description

Alpha
Beta
Gamma
NCT04505722
Janssen Pharmaceutical Companies
Sadoff J, N Engl J Med, 2022
ENSEMBLE

Full text
Commentary
Non replicating viral vector

Ad26.COV2.S

Placebo

RCT
Phase 3
Adults >18 years of age at 213 centers in Argentina, Brazil, Chile, Colombia, Mexico, Peru, South Africa and USA N=44325 Variant beta:

Some concerns
Details

Full description

Alpha
Beta
Delta
RPCEC00000347
Instituto Finlay de Vacunas
Toledo-Romani ME, medRxiv, 2022

Full text
Commentary
Commentary
Protein subunit

SOBERANA 02/SOBERANA plus

Adjuvant

RCT
Phase 2b
Healthy adults with no known or suspected history of COVID-19 at 2 centers in Cuba. N=810
Some concerns
Details

Full description

Alpha
Beta
Delta
NCT04471519; CTRI/2021/04/032942
Bharat Biotech
Vadrevu KM, Sci Rep, 2022
Updated

Full text
Full text
Commentary
Commentary
Inactivated virus

BBV152/Boost

Placebo

RCT
Phase 2
Adolescents and adults aged 12-64 years with no history of confirmed COVID-19, who had received a 2-dose schedule of the same vaccine 6 months previously at 9 centers in India. N=184
Some concerns
Details

Full description