The BNT162b2 mRNA Covid-19 vaccine, developed by BioNTech and Pfizer, was found to be safe and highly effective in preventing Covid-19. In a multinational, placebo-controlled trial, 43,548 participants aged 16 years or older were randomly assigned to receive either two doses of BNT162b2 (30 μg per dose, 21 days apart) or a placebo. The primary endpoints were efficacy against laboratory-confirmed Covid-19 and safety. The results showed that BNT162b2 was 95% effective in preventing Covid-19, with a 95% credible interval of 90.3 to 97.6. Similar efficacy was observed across various subgroups, including age, sex, race, ethnicity, body-mass index, and the presence of coexisting conditions. The safety profile was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache, with a low incidence of serious adverse events. The study concluded that a two-dose regimen of BNT162b2 provided 95% protection against Covid-19 and had a safety profile similar to other viral vaccines.The BNT162b2 mRNA Covid-19 vaccine, developed by BioNTech and Pfizer, was found to be safe and highly effective in preventing Covid-19. In a multinational, placebo-controlled trial, 43,548 participants aged 16 years or older were randomly assigned to receive either two doses of BNT162b2 (30 μg per dose, 21 days apart) or a placebo. The primary endpoints were efficacy against laboratory-confirmed Covid-19 and safety. The results showed that BNT162b2 was 95% effective in preventing Covid-19, with a 95% credible interval of 90.3 to 97.6. Similar efficacy was observed across various subgroups, including age, sex, race, ethnicity, body-mass index, and the presence of coexisting conditions. The safety profile was characterized by short-term, mild-to-moderate pain at the injection site, fatigue, and headache, with a low incidence of serious adverse events. The study concluded that a two-dose regimen of BNT162b2 provided 95% protection against Covid-19 and had a safety profile similar to other viral vaccines.