Pfizer and BioNTech said their COVID-19 vaccine was 91.3% effective against COVID-19 from day 7 through six months after the second dose in their Phase 3 clinical trial, according to a news release.
The updated results included an analysis of 927 confirmed symptomatic cases of COVID-19 observed in the Phase 3 study through March 13, 2021. From the 927 confirmed symptomatic cases of COVID-19 in the trial, 850 cases of COVID-19 were in the placebo group and 77 cases were in the BNT162b2 group.
In addition, the vaccine, BNT162b2, was 100% effective against severe disease as defined by the U.S. Centers for Disease Control and Prevention (CDC), and 95.3% effective against severe COVID-19 as defined by the U.S. Food and Drug Administration (FDA)
In South Africa, where the B.1.351 lineage is prevalent and 800 participants were enrolled, nine cases of COVID-19 were observed, all in the placebo group, indicating vaccine efficacy of 100%.
