Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months

• Published in: New England Journal of Medicine 2021-11
• Main Authors: Thomas, Stephen J, Moreira, Edson D, Kitchin, Nicholas, Absalon, Judith, Gurtman, Alejandra, Lockhart, Stephen, Perez, John L, Gonzalo Pérez Marc, Polack, Fernando P, Zerbini, Cristiano, Bailey, Ruth, Swanson, Kena A, Xu, Xia, Roychoudhury, Satrajit, Koury, Kenneth, Bouguermouh, Salim, Kalina, Warren V, Cooper, David, Frenck, Robert W, Hammitt, Laura L, Türeci, Özlem, Haylene Nell, Schaefer, Axel, Ünal, Serhat, Yang, Qi, Liberator, Paul, Tresnan, Dina B, Mather, Susan, Dormitzer, Philip R, Şahin, Uğur, Gruber, William C, Jansen, Kathrin U
• Format: Article
• Language: English
• Subjects: COVID-19 vaccines
• DOI: 10.1056/NEJMoa2110345

Background BNT162b2 is a lipid nanoparticle–formulated, nucleoside-modified RNA vaccine encoding a prefusion-stabilized, membrane-anchored severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) full-length spike protein. BNT162b2 is highly efficacious against coronavirus disease 2019 (Covid-19) and is currently approved, conditionally approved, or authorized for emergency use worldwide. At the time of initial authorization, data beyond 2 months after vaccination were unavailable. Methods In an ongoing, placebo-controlled, observer-blinded, multinational, pivotal efficacy trial, we randomly assigned 44,165 participants 16 years of age or older and 2264 participants 12 to 15 years of age to receive two 30-μg doses, at 21 days apart, of BNT162b2 or placebo. The trial end points were vaccine efficacy against laboratory-confirmed Covid-19 and safety, which were both evaluated through 6 months after vaccination. Results BNT162b2 continued to be safe and have an acceptable adverse-event profile. Few participants had adverse events leading to withdrawal from the trial. Vaccine efficacy against Covid-19 was 91.3% (95% confidence interval [CI], 89.0 to 93.2) through 6 months of follow-up among the participants without evidence of previous SARS-CoV-2 infection who could be evaluated. There was a gradual decline in vaccine efficacy. Vaccine efficacy of 86 to 100% was seen across countries and in populations with diverse ages, sexes, race or ethnic groups, and risk factors for Covid-19 among participants without evidence of previous infection with SARS-CoV-2. Vaccine efficacy against severe disease was 96.7% (95% CI, 80.3 to 99.9). In South Africa, where the SARS-CoV-2 variant of concern B.1.351 (or beta) was predominant, a vaccine efficacy of 100% (95% CI, 53.5 to 100) was observed. Conclusions Through 6 months of follow-up and despite a gradual decline in vaccine efficacy, BNT162b2 had a favorable safety profile and was highly efficacious in preventing Covid-19. (Funded by BioNTech and Pfizer; ClinicalTrials.gov number, NCT04368728.)