Why Pfizer and BioNTech's COVID Vaccine Could Be Even Better Than Expected

Last week, Pfizer and BioNTech announced updated results from their late-stage study that served as the basis for winning Emergency Use Authorization (EUA) for BNT162b2. Probably the most surprising new information from those results was that the vaccine was 100% effective in preventing COVID-19 in South Africa, where a coronavirus variant named B.1.351 is running rampant.