Our estimates of the effectiveness of two doses of the BNT162b2 vaccine against all SARS-CoV-2 infections of 36.8% (95% CI, 35.3 to 38.2) and against PCR-confirmed SARS-CoV-2 infections of 65.3% (95% CI, 62.0 to 68.3) among children 5 to 11 years of age during the omicron wave are lower than those in previous studies that were conducted when other variants were predominant.7,11 A vaccine efficacy of 90.7% (95% CI, 67.7 to 98.3) was reported in a phase 2–3 clinical trial involving 2268...
