The Pfizer/BioNTech COVID-19 vaccine is 91.3% effective up to 6 months after the second dose and 100% effective against severe disease as defined by the US Centers for Disease Control and Prevention (CDC), according to updated data today from the phase 3 trial.
The vaccine was also 100% effective at preventing illness among trial participants in South Africa, where the highly transmissible B1351 variant is dominant, the Pfizer news release said. No safety issues were identified among the more than 44,000 participants 16 years or older over at least 6 months' follow-up after the second shot.