Safety outcomes following COVID-19 vaccination and infection in 5.1 million children in England

This study examined safety outcomes in 5.1 million children in England following COVID-19 vaccination and infection. In younger children aged 5-11, no increased risks of adverse events were found after vaccination. In adolescents aged 12-17, the study identified very small increases in myocarditis cases and some other serious conditions following vaccination, but found that infection with SARS-CoV-2 carried higher risks of hospitalization, which were largely prevented by prior vaccination. Overall, the researchers concluded that COVID-19 vaccination has a favourable safety profile in children under 18.

Key points

• No increased risks of adverse events in 5-11-year-olds within 42 days of vaccination with any of three COVID-19 vaccines
• In 12-17-year-olds, 3-5 additional myocarditis cases per million were estimated after first and second BNT162b2 doses
• An additional 12 epilepsy hospitalizations and 4 demyelinating disease cases per million estimated after second BNT162b2 dose in adolescents
• SARS-CoV-2 infection carried substantially increased hospitalization risks from seven outcomes including myocarditis and multisystem inflammatory syndrome
• Vaccination prior to infection largely prevented hospitalization risks from COVID-19 infection

Limitations

The study is observational and uses a self-controlled case-series design, which compares individuals to themselves over time rather than between vaccinated and unvaccinated groups, potentially limiting causal inference. The absolute numbers of additional adverse events per million, while very small, rely on confidence intervals that cross zero for some outcomes, indicating uncertainty in the estimates.