COVID-19 vaccine effectiveness on variants of concern
(Randomized evidence)
Methods
Variants of concern
Please choose a variant of concern
Description of primary studies
| Trial | Type | Comparisons | Design | Participants | Sample size | Overall risk of bias Highest assessment |
Full description | |
|---|---|---|---|---|---|---|---|---|
| Intervention 1 | Intervention 2 | |||||||
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Gamma Delta NCT04672395 Clover Biopharmaceuticals Inc./Dynavax Bravo L, Lancet, 2022 Full text Commentary Commentary |
Protein subunit |
SCB-2019 |
Placebo |
RCTPhase 2-3 | Healthy adults or with stable chronic conditions, both SARS-CoV-2 seropositive and seronegative, at 31 centers in Belgium, Brazil, Colombia, Philippines, and South Africa. | N=30174 |
Variant delta: Some concerns Details |
|
|
ChiCTR2100051998 Sinovac Research and Development Co. Ltd.; Anhui Zhifei Longcom Biopharmaceutical + Institute of Microbiology, Chinese Academy of Sciences Cao Y, Cell Res, 2021 Full text Commentary |
Inactivated virus |
CoronaVac/Boost ZF2001 |
CoronaVac/Boost CoronaVac |
RCTPhase 2 | Healthcare professionals with no previous confirmed COVID-19 at a single center in China who had received two doses of CoronaVac in a 28-day interval 4–8 months earlier | N=164 |
Some concerns Details |
|
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Gamma ISRCTN89951424 AstraZeneca+University of Oxford Clemens S, Nat. Commun., 2021 Full text Commentary Commentary |
Non replicating viral vector |
ChAdOx1 |
MenACWY |
RCTPhase 3 | Adults that were SARS-CoV-2 seronegative and with no history of COVID-19 in six centers in Brazil. | N=10416 |
Variant gamma: Some concerns Details |
|
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NCT05087368 Clover Biopharmaceuticals Inc./Dynavax ; AstraZeneca + University of Oxford Costa Clemens, Open Forum Infect. Dis., 2022 Full text Commentary Commentary Commentary Commentary |
Protein subunit |
ChAd/boost9mcgSCB-2019+al ChAd/B*9SCB-2019+al+CpG ChAd/B*30SCB-2019+al+CpG |
ChadOx1/boostChadOx1 |
RCTPhase 2 | Adults including healthy or stable co-morbidities with no history of SARS-CoV-2 infection who had previously received 2 doses of ChAdOx1-S1-S vaccine 6 months (±4 weeks) before enrollment in 3 centers in Brazil | N=120 |
Some concerns Details |
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RBR–9nn3scw AstraZeneca+University of Oxford/Sinovac/Janssen Pharmaceutical Companies/Pfizer/BioNTech+Fosun Pharma Costa Clemens SA, Lancet, 2022 Full text Commentary Commentary |
Non replicating viral vector |
CoronaVac/Boost BNT162b2 CoronaVac/Boost ChAd CoronaVac/Boost AD26 |
CoronaVac/Boost CoronaVac |
RCTPhase 4 | Healthy adults with no history of confirmed covid-19 who had previously received 2 doses of CoronaVac at two centers in Brazil | N=1240 |
Some concerns Details |
|
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Delta NCT04796896 ModernaTX Creech CB, N Engl J Med, 2022 KidCOVE Full text Commentary |
RNA based vaccine |
mRNA-1273 (50 mcg) |
Placebo |
RCTPhase 2-3 | Children aged 6-11 years, healthy or with stable chronic conditions and no known recent history of COVID-19 infection, at 87 centers in Canada and USA. | N=4016 |
Variant delta: Some concerns Details |
|
|
Alpha Gamma Delta NCT04646590 Anhui Zhifei Longcom Biopharmaceutical Dai L, N Engl J Med, 2022 Full text Commentary Commentary |
Protein subunit |
ZF2001 |
Placebo |
RCTPhase 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 |
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Alpha NCT04611802 Novavax Dunkle L M, N Engl J Med, 2021 Full text Commentary |
Protein subunit |
NVX-CoV2373 |
Placebo |
RCTPhase 3 | Healthy adults in 113 sites in the USA and 6 in Mexico | N=29949 |
Some concerns Details |
|
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Alpha Delta NCT04641481 Bharat Biotech Ella R, Lancet, 2021 Full text Commentary |
Inactivated virus |
BBV152 |
Adjuvant |
RCTPhase 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 |
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Alpha NCT04400838 AstraZeneca+University of Oxford Emary K, Lancet, 2021 Full text Commentary |
Non replicating viral vector |
ChAdOx1 |
MenACWY |
RCTPhase 2-3 | Adults seronegative at baseline enrolled at 19 study sites in UK | N=10673 |
Variant alpha: Some concerns Details |
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Alpha Beta Gamma Delta NCT04636697 Medicago Inc Hager K, N Engl J Med, 2022 Full text Full text Commentary |
Virus-Like particle |
CoVLP |
Placebo |
RCTPhase 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 |
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Alpha NCT04526990 CanSino Biological Inc./Beijing Institute of Biotechnology Halperin SA, Lancet, 2021 Full text Commentary Commentary |
Non replicating viral vector |
Ad5-nCoV |
Adjuvant |
RCTPhase 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 |
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Alpha NCT04614948 Janssen Pharmaceutical Companies Hardt K, Lancet Infect Dis, 2022 ENSEMBLE2 Full text Full text Commentary |
Non replicating viral vector |
Ad26.COV2.S |
Placebo |
RCTPhase 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 |
|
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Alpha Beta Gamma Delta NCT04614948 Janssen Pharmaceutical Companies Hardt K, Lancet Infect Dis, 2022 ENSEMBLE2 Full text Full text Commentary |
Non replicating viral vector |
Ad26.COV2.S Ad26.COV2.S |
Placebo |
RCTPhase 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 |
|
|
Alpha NCT04583995; EudraCT 2020-004123-16 Novavax Heath P, Clin Infect Dis, 2022 Full text Commentary |
Protein subunit |
NVX-CoV2373 |
Placebo |
RCTPhase 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=15185 |
Variant alpha: Some concerns Details |
|
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Beta RPCEC00000359 Center for Genetic Engineering and Biotechnology (CIGB) Hernandez-Bernal F, SSRN, 2022 Abdala-3 Full text Commentary Commentary Commentary |
Protein subunit |
Abdala |
Placebo |
RCTPhase 3 | Adults, healthy or with controlled co-morbidities and no history of SARS-CoV-2 at 18 centers in Cuba | N=48290 |
Some concerns Details |
|
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Alpha Beta Delta NCT04649021 Pfizer/BioNTech+Fosun Pharma Hui A-M, Lancet, 2022 Full text Full text Commentary Commentary |
RNA based vaccine |
BNT162b2 |
Placebo |
RCTPhase 2 | Healthy adults and those with a pre-existing stable condition, at 2 centers in China. | N=960 |
Low Details |
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TCTR20211004001 Sinovac/Pfizer-BioNTech+Fosun Pharma Intapiboon P, Vaccines, 2021 Full text Commentary |
Heterologous booster |
CoronaVac/boostBNT16(1:2) CoronaVac/boostBNT(1:5)ID |
CoronaVac/boostBNT16 |
RCTPhase 1 | Healthy adults who had reecived 2 doses CoronaVac with no current or known history of SARS-CoV-2 infection at a single center in Thailand | N=91 |
Some concerns Details |
|
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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 |
RCTPhase 2 | Adults with no known or suspected history of SARS-CoV-2 infection at 17 centers in France. | N=414 |
Some concerns Details |
|
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Delta CTRI/2021/01/030416 Zydus Cadila Khobragade A, Lancet , 2022 Full text Commentary |
DNA based vaccine |
ZyCoV-D |
Placebo |
RCTPhase 3 | Healthy adults and adolescents aged (≥12 years) with no previous history of COVID-19 at 49 centers in India. | N=27703 |
Variant delta: Some concerns Details |
|
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Beta Delta NCT04444674 AstraZeneca + University of Oxford Koen A, medRxiv, 2022 COV005 Full text Full text Commentary |
Non replicating viral vector |
ChAdOx1 |
Placebo |
RCTPhase 1-2 | Healthy adults aged 18–65 years in 7 centres in South Africa | N=2130 |
Variant beta: Some concerns Details |
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Alpha Gamma NCT04652102; EudraCT 2020-003998-22 CureVac AG Kremsner P, Lancet Infect Dis, 2022 HERALD Full text Commentary |
RNA based vaccine |
CVnCoV |
Placebo |
RCTPhase 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 |
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EudraCT, 2022-000063-51; NCT05249829 ModernaTX/National Institute of Allergy and Infectious Diseases (NIAID) Lee l, medRxiv, 2023 Full text Commentary Commentary |
Heterologous booster |
2nd Boost mRNA-1273.214 |
2nd Boost mRNA-1273 |
RCTPhase 2-3 | Healthy or stable co-morbidities, at least 16 years who had previously received 2 injections of an authorized Covid-19 primary series vaccine with or without an mRNA-based booster as the third dose in 28 centres in UK. | N=2824 |
Some concerns Details |
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Beta NCT04533399; PACTR202009726132275 Novavax Madhi S, Lancet HIV, 2022 Full text Commentary |
Protein subunit |
NVX-CoV2373 |
Placebo |
RCTPhase 2 | HIV-negative adults (18 to 84 years) and medically stable HIV-positive adults (18 to 64 years) at 16 sites in South Africa | N=4419 |
Variant beta: Some concerns Details |
|
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NCT04368988 Novavax Mallory R, Lancet Infect Dis, 2022 Full text Full text Commentary Commentary |
Protein subunit |
NVX-CoV2373 boost |
NVX-CoV2373 |
RCTPhase 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 | |
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NCT04611243 Sinovac/Pfizer/BioNTech+Fosun Pharma Mok C K P, Am. J. Respir. Crit., 2022 Full text Commentary |
RNA based vaccine |
CoronaVac/Boost |
CoronaVac/Boost BNT162b2 |
RCT* | Adults that had received two doses of CoronaVac but had low immune response against SARS-CoV-2 at two centres in Hong Kong, China | N=80 |
Some concerns Details |
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A, Lancet, 2021 COV-BOOST Full text Commentary |
Heterologous booster |
ChadOx1/boostm1273 ChadOx1/boostCVn ChadOx1/boostBNT(half) |
ChadOx1/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=462 |
Some concerns Details |
|
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A, Lancet, 2021 COV-BOOST Full text Commentary |
Heterologous booster |
BNT162b2/boostChAd BNT162b2/boostNVX BNT162b2/boostNVX(half) |
BNT162b2/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=453 |
Some concerns Details |
|
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A, Lancet, 2021 COV-BOOST Full text Commentary |
Heterologous booster |
BNT162b2/boostm1273 BNT162b2/boostCVn BNT162b2/boostBNT(half) |
BNT162b2/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=439 |
Some concerns Details |
|
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A, Lancet, 2021 COV-BOOST Full text Commentary |
Heterologous booster |
ChadOx1/boostBNT ChadOx1/boostVLA ChadOx1/boostVLA(half) ChadOx1/boostAd26 |
ChadOx1/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=541 |
Some concerns Details |
|
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A , Lancet, 2021 COV-BOOST Full text Commentary |
Non replicating viral vector |
ChadOx1/boost ChadOx1/boostNVX ChadOx1/boostNVX ChadOx1/boostNVX(half) ChadOx1/boostNVX(half) |
ChadOx1/Placebo ChadOx1/Placebo ChadOx1/boost ChadOx1/boost ChadOx1/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=443 |
Some concerns Details |
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ISRCTN73765130 AstraZeneca + University of Oxford; Janssen Pharmaceutical; Novovax; Moderna + NIAID; Pfizer BioNTech + Fosun Pharma; CureVac AG; Valneva, NIHR, UK Munro A, Lancet, 2021 COV-BOOST Full text Commentary |
RNA based vaccine |
BNT162b2/boost BNT162b2/boostVLA BNT162b2/boostVLA(half) BNT162b2/boostAd26 |
BNT162b2/Placebo |
RCTPhase 2 | Adults aged ≥30 years in good physical health at 18 centers in the UK. | N=545 |
Some concerns Details |
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TCTR20210722003 AstraZeneca+University of Oxford Nanthapisal S, Vaccine, 2022 Full text Commentary Commentary |
Non replicating viral vector |
CoronaVac/Boost ChAd |
CoronaVac/Boost ChAd(LD) |
RCTPhase 2 | Healthy adult volunteers with no history or current infection with SARS-CoV-2 who had completed two doses of CoronaVac at 2 centres in Thailand. | N=422 |
Some concerns Details |
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NCT04922788 Nanogen Pharmaceutical Biotechnology JSC. Nguyen TP, medRxiv, 2022 Full text Commentary Commentary |
Protein subunit |
Nanocovax |
Placebo |
RCTPhase 3 | Healthy adult without previous or current SARS-CoV-2 infection in four centres in Vietnam. | N=13007 |
Variant delta: Some concerns Details |
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Beta Gamma NCT04764422 The Government Pharmaceutical Organization (GPO); PATH; Dynavax Pitisuttithum P, medRxiv, 2021 Full text Commentary Commentary |
Inactivated virus |
NDV-HXP-S 1mcg NDV-HXP-S 1mcg + CpG1018 NDV-HXP-S 3mcg NDV-HXP-S 3mcg + CpG1018 NDV-HXP-S 10mcg NDV-HXP-S 1mcg |
Placebo |
RCTPhase 1 | Healthy adults without immunosuppression negative for SARS-CoV-2 antibodies at a single center in Thailand | N=210 |
Some concerns Details |
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NCT05142319 Pfizer/BioNTech+Fosun Pharma; ModernaTX Poh XY, Clin. Infect. Dis., 2022 PRIBIVAC Full text Commentary |
RNA based vaccine |
BNT162b2/boostm1273 |
BNT162b2/boostBNT |
RCT3 | 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 |
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NCT04505722 Janssen Pharmaceutical Companies Sadoff J, N Engl J Med, 2022 ENSEMBLE Full text Full text Commentary |
Non replicating viral vector |
Ad26.COV2.S |
Placebo |
RCTPhase 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 |
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Beta Delta NCT04762680 Sanofi Pasteur+GlaxoSmithKline Sridhar S, Lancet Infect Dis , 2022 Full text Commentary |
Protein subunit |
CoV2 preS dTM 15 mcg CoV2 preS dTM 10 mcg |
CoV2 preS dTM 5 mcg |
RCTPhase 2 | Adults with and without prior SARS-CoV-2 infection and risk factors for severe disease at 20 centers in the USA and Honduras | N=722 |
Some concerns Details |
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Beta Delta ISRCTN27841311; EudraCT 2021-001275-16 AstraZeneca + University of Oxford / Novavax / Moderna + NIAID Stuart A, Lancet, 2021 Com-COV2 Full text Commentary Commentary |
Protein subunit |
ChAd/NVX-CoV2373 ChAd/mRNA-1273 |
ChAdOx1 |
RCTPhase 2 | Healthy adults over 50 years previously vaccinated with one dose of ChAdOx1 nCoV-19 in 9 centres in the UK | N=540 |
Some concerns Details |
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Beta Delta ISRCTN27841311; EudraCT 2021-001275-16 Pfizer BioNTech + Fosun Pharma / Novavax / Moderna + NIAID Stuart A, Lancet, 2021 Com-COV2 Full text Commentary Commentary |
Protein subunit |
BNT/NVX-CoV2373 BNT/mRNA-1273 |
BNT162b2 |
RCTPhase 2 | Adults over 50 years previously vaccinated with one dose of BNT162b2 at 9 centres in the UK | N=532 |
Some concerns Details |
|
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Beta NCT04368728 Pfizer/BioNTech+Fosun Pharma Thomas S, N Engl J Med, 2021 Full text Commentary Commentary |
RNA based vaccine |
BNT162b2 |
Placebo |
RCTPhase 2-3 | Children (>=12Y yo), adolescentes and adults, with no history or SARS-CoV 2 infection at 152 sites in Argentina, Brazil, Germany, South Africa, Turkey and USA | N=44165 |
Variant beta: Some concerns Details |
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Delta CTRI/2021/08/036074 Biological E;AstraZeneca+University of Oxford Thuluva , medRxiv, 2022 Full text Commentary Commentary |
Protein subunit |
BECOV2 |
ChAdOx1 |
RCTPhase 3 | Healthy adults without a history of Covid-19 vaccination or SARS-CoV-2 infection at 20 centers in India. | N=2140 |
Some concerns Details |
|
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Delta CTRI/2021/10/037066 Biological E. Limited Thuluva S, Vaccine, 2022 Full text Full text Commentary Commentary Commentary |
Protein subunit |
BECOV2 ≥5 to <12 BECOV2 ≥12 to <18 |
Placebo |
RCTPhase 2-3 | Healthy children and adolescents who were SARS-CoV-2 RT-PCR and anti-SARS-CoV-2 antibody negative in 23 centers in India | N=390 |
Low Details |
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Alpha Beta Delta RPCEC00000347 Instituto Finlay de Vacunas Toledo-Romani ME, Med, 2022 Full text Commentary Commentary Commentary |
Protein subunit |
SOBERANA 02/SOBERANA plus |
Adjuvant |
RCTPhase 2b | Healthy adults with no known or suspected history of COVID-19 at 2 centers in Cuba. | N=810 |
Some concerns Details |
|
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NCT04471519; CTRI/2021/04/032942 Bharat Biotech Vadrevu KM, Sci Rep, 2022 Full text Full text Commentary Commentary |
Inactivated virus |
BBV152/Boost |
Placebo |
RCTPhase 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 |
|
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Delta NCT04816643 Pfizer/BioNTech+Fosun Pharma Walter E, N Engl J Med, 2021 Full text Commentary |
RNA based vaccine |
BNT162b2 10 mcg |
Placebo |
RCTPhase 2-3 | Children aged 5-11 years with or without stable co-morbidities with no history of COVID-19 in 81 centres in the USA, Spain, Finland, and Poland | N=2285 |
Variant delta: Some concerns Details |
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ChiCTR2100051391 Beijing Wantai Biological Pharmacy Enterprise Co., Ltd. Xia N, Research Square, 2023 Full text Commentary |
Heterologous booster |
Any prime/Boost dNS1-RBD |
Any prime/Boost placebo |
RCTPhase 3 | Adultsincluding healthy and mild stable co-morbidities without prior COVID-19 history in 33 centres in Philippines, South Africa, Colombia and Vietnam | N=17210 |
Some concerns Details |
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