Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine
This multinational, randomized, placebo-controlled phase 2/3 trial evaluated the safety and efficacy of two 30-µg doses of the BNT162b2 lipid-nanoparticle mRNA vaccine, given 21 days apart, in 43,548 participants 16 years of age or older. Among those without prior SARS-CoV-2 infection, the vaccine conferred 95% protection against laboratory-confirmed Covid-19 beginning at least 7 days after the second dose. The safety profile over a median of about two months was characterized by short-lived, mostly mild-to-moderate reactions, with a low incidence of serious adverse events comparable to placebo.