Overview
- The Lancet Child & Adolescent Health analysis linked electronic health records for about 98% of England’s under-18s from January 2020 to December 2022, led by teams at Cambridge, Edinburgh and UCL with data accessed in the NHS England Secure Data Environment.
- Over six months, the study estimated 2.24 additional myocarditis or pericarditis cases per 100,000 after a first COVID-19 infection versus 0.85 additional cases per 100,000 after a first Pfizer–BioNTech dose.
- Risks after a first infection peaked in the first four weeks and for several outcomes stayed elevated for up to 12 months, whereas the vaccine-associated myocarditis or pericarditis risk was short-lived, largely confined to the first 4–6 weeks.
- Researchers assessed rare outcomes including myocarditis, pericarditis, arterial and venous thrombosis, thrombocytopenia, and inflammatory syndromes such as PIMS and Kawasaki disease.
- The analysis covered 3.9 million first COVID-19 diagnoses and 3.4 million first vaccinations and evaluated only first events, with authors cautioning that repeated infections, boosters and newer variants could alter future risk profiles and warrant ongoing monitoring.