Effectiveness of BNT162b2 Vaccine against Delta Variant in Adolescents

Abstract

The B.1.617.2 (delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as the dominant strain circulating in many regions worldwide. The BNT162b2 mRNA vaccine against coronavirus disease 2019 (Covid-19) was found to be effective in preventing infection with the delta variant in a recent observational study,¹ but other reports have suggested reduced vaccine effectiveness against this variant.^2,3 On May 10, 2021, the U.S. Food and Drug Administration approved the emergency use of BNT162b2 in adolescents 12 years of age or older on the basis of a clinical trial that had been conducted before the delta variant had become prevalent in the United States.⁴ Additional evidence was needed regarding the effectiveness of the BNT162b2 vaccine among adolescents, particularly against the delta variant.