Vaccine name Types of vaccines Efficacy and immune responses
BNT162b2
mRNA vaccines
95% effective in preventing COVID-19 Induced IgG antibodies had higher avidity to mutated RBD than those induced by natural infection66,183,191
Moderna
mRNA vaccines
94.1% efficacy at preventing COVID-19 Preclinical testing in advanced clinical evaluation has shown a Th1-skewed vaccine response and no pathologic lung infiltrates192-194
AZD1222
Viral vector After the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81.3% at ≥12 weeks) than in those with a short interval (vaccine efficacy 55.1% at <6 weeks) Higher binding and neutralizing antibody titers in sera with a longer prime-boost interval195
Sputnik V
Viral vector 91.6% efficacious against COVID-19 (from day 21 after the first dose, to the day of receiving the second dose) RBD-specific IgG was detected in 98% of samples, with a geometric mean titer (GMT) of 8996, and a seroconversion rate of 98.25% Increased SARS-CoV-2 neutralizing antibody titers By day 28 after the first vaccination, all vaccinated participants had significantly higher levels of IFN-γ secretion upon antigen restimulation compared with the day of administration of the first dose196
Ad26.COV2.S
Viral vector The level of protection for the combined endpoints of moderate and severe disease varied: 72% in the United States; 66% in Latin American countries; and 57% in South Africa, 28 days post-vaccination. The investigated vaccine was reportedly 85% effective in preventing severe/critical COVID-19 across all geographical regions. Induced durable protection at low doses in preclinical SARS-CoV-2 challenge studies; initial clinical data showed that a single dose at 5×1010 viral particles was safe and induced excellent humoral and cellular immune responses197-200
BBIBP COVID-19 vaccine
Inactivated vaccines
Sinopharm has announced an efficacy of 79% A sharp increase in antibody concentrations was observed following SARS-CoV-2 infection after the first and second doses177,187,201
Covaxin (BBV152) Viral vector 81% interim efficacy in preventing COVID-19 in those without prior infection after the 2nd dose In the phase 1 trial, BBV152 induced high neutralizing antibody responses that remained elevated at 3 months after the 2nd vaccination In the phase 2 trial, BBV152 enhanced humoral and cell-mediated immune responses compared with the phase 1 trial202
CoronaVac
Inactivated virus Multiple studies in different countries: 50.7% (Brazil), 56.5% (Chile), 65% (Indonesia), 78% (Brazil) and 91% (Turkey) Immune responses in phase 2 were much better than those recorded in phase 1; seroconversion rates over 90% in both the 3 μg and 6 μg groups Well tolerated and induced humoral responses against SARS-CoV-2 In an exploratory analysis by age, seroconversion rates at day 28 after the second dose were higher than 94% in the 3 μg and 6 μg groups for participants aged 60-64 years, 65-69 years, and 70 years or older, with GMTs ranging from 36.4 to 55.2201,203,204
AD5-nCOV
Viral vector Tolerable and immunogenic in healthy adults. Specific humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination, and rapid, specific T-cell responses were noted from day 14 after one shot of the vaccine Aerosolized Ad5-nCoV is well tolerated, and two doses of aerosolised Ad5-nCoV elicited neutralizing antibody responses, similar to one dose of intramuscular injection. An aerosolized booster vaccination at 28 days after first intramuscular injection induced strong IgG and neutralizing antibody responses205,206
CV2CoV
Unmodified RNA vaccines
Induced higher titers of binding and neutralizing antibodies against SARS-COV-2 variants, and memory B and T cell responses non-human primates186.
PreS-RBD vaccine
Recombinant fusion protein
Median inhibitions of RBD to ACE2 (100 ng RBD: 8.6% to 98.3% inhibition, median inhibition: 16.0%; 50 ng RBD: 14.4% to 99.4% inhibition, median inhibition: 52.8%) Robust anti-RBD IgG response in rabbits consisting of an early IgG1 and sustained IgG4 which can be detected in serum and mucosa secretions The vaccine-induced antibodies potently inhibited the interaction of RBD with ACE2 and possessed the neutralizing ability to the omicron VOC190.
NVX-CoV2373
Protein subunit A two-dose regimen of the NVX-CoV2373 vaccine administered to adult participants conferred 89.7% protection against SARS-CoV-2 infection and showed high efficacy against the B.1.1.7 variant Elicited immune responses that exceeded levels in COVID-19 convalescent serum207,208