Effectiveness of COVID-19 vaccines against the Delta variant
This case-control study compares the effectiveness of Pfizer-BioNTech (BNT162b2) and Covishield (ChAdOx1 nCoV-19) Vaccines against the Alpha and Delta variants.
Both the vaccines showed a rise in its effectiveness after administration of Dose 2.
BNT162b2 has 93.7% and 88%, while ChAdOx1 nCoV-19 shows 74.5% and 67% effectiveness against Alpha and Delta variants, respectively.
Safety and efficacy of Sputnik V vaccine: Phase 3 results.
This study was conducted on 21977 individuals, 18 years and above at 25 centres in Russia. The participants were randomly assigned to placebo and vaccines by 1:3 ratio. The vaccine vector components for dose 1 and dose 2 are rAd26-S and rAd5-S, respectively. The study reported 87.6% and 91.6% efficacy at 14- and 21-days post-dose 1. The efficacy of the vaccine after dos 2 was found to be 91.1%.
