Pfizer remarks in updated data on its COVID-19 vaccine

  • Vaccine is around 91% effective at preventing COVID-19 (down from 95%)
  • Vaccine was 100% effective in preventing illness among trial participants in South Africa, where the B1351 variant is dominant
  • Vaccine was 100% effective in preventing severe disease as defined by the CDC
  • Vaccine was 95% effective in preventing severe disease as defined by the FDA

The headline will make for comfortable reading amid fears that the virus variants will throw a wrench in the works on the global recovery. That said, the trial sample size in South Africa is rather small i.e. 800 participants only.

Pfizer also adds that there were no serious safety concerns observed in all trial participants for up to six months after the second dose was administered.