The COVID-19 vaccine shots are highly effective against hospitalization and death. Researchers conducted a study of eight vaccines and according to the research, all the vaccines except the Sinovac vaccine have over 80 per cent efficacy. According to the new research published in the pre-print, the vaccines showed 85 per cent efficacy against the coronavirus after administration of both doses of vaccine.
The University of Florida researchers compared data from journal articles and media reports for products that have gone through double-blinded, placebo-controlled, late-stage vaccine trials and observational studies. The researchers conducted the study of Pfizer, Moderna, Johnson & Johnson, AstraZeneca, Sputnik, Novavax, Sinovac and Sinopharm. As per the study, the vaccines showed almost 100 per cent protection against severe disease, hospitalization or death. The researchers indicate vaccination reduces the spread of infection to others by 54 per cent. According to the research, one dose of the Moderna vaccine reduces virus transmission by at least 61 per cent.
The study showed vaccine effectiveness against PCR-confirmed infection with the B.1.351 variant. The vaccine proved protective against severe, critical, or fatal disease caused by the B.1.351 variant. For B.1.1.7 variant, vaccine efficacy is 86 per cent, which is reduced in the more infectious virus. The vaccines showed 61 per cent efficacy against B.1.1.28 variant and 56 per cent efficacy against B.1.351 COVID-19 variant.
The researchers in the paper said that these estimates should be useful for constructing mathematical models for immunization impact and for making policy decisions involving vaccination. For the study, the scientists obtained log odds ratios and corresponding sampling variances from each vaccine efficacy estimate and a 95 per cent confidence interval (CI). The random-effects models were used to estimate average log odds ratios, which were transformed to obtain vaccine efficacy summary estimates and 95 per cent confidence interval.