OpenSAFELY: Effectiveness of COVID-19 vaccination in children and adolescents

Background: We assessed the safety and effectiveness of first and second dose BNT162b2 COVID-19 vaccination, offered as part of the national COVID-19 vaccine roll-out from September 2021, in children and adolescents in England. Methods: Our observational study using OpenSAFELY-TPP, included adolescents aged 12-15 years, and children aged 5-11 years. It compared individuals receiving i) first vaccination to unvaccinated controls and ii) second vaccination to single-vaccinated controls. We matched vaccinated individuals with controls on age, sex, and other important characteristics. Outcomes were positive SARS-CoV-2 test (adolescents only); COVID-19 accident and emergency (A&E) attendance; COVID-19 hospitalization; COVID-19 critical care admission; COVID-19 death, with safety outcomes A&E attendance, unplanned hospitalization, pericarditis, and myocarditis. Results: Amongst 820,926 previously unvaccinated adolescents, 20-week incidence rate ratios (IRR) comparing vaccination with no vaccination were 0.74 for positive SARS-CoV-2 test, 0.60 for COVID-19 A&E attendance and 0.58 for COVID-19 hospitalization. Amongst 441,858 adolescents who had received first vaccination IRRs comparing second dose with single-vaccination were 0.67 for positive SARS-CoV-2 test, 1.00 for COVID-19 A&E attendance and 0.60 for COVID-19 hospitalisation. In both children groups COVID-19-related outcomes were too rare to allow IRRs to be estimated precisely. Across all analyses there were no COVID-19-related deaths, and fewer than seven COVID-19-related critical care admissions. Myocarditis and pericarditis were documented only in the vaccinated groups, with rates of 27 and 10 cases/million after first and second doses respectively. Conclusions: BNT162b2 vaccination in adolescents reduced COVID-19 A&E attendance and hospitalisation, although these outcomes were rare. Protection against positive SARS-CoV-2 tests was transient.