evidence: The association between COVID-19 vaccination and cardiac events using confirmed cases and hospital admissions with diagnoses of myocarditis or pericarditis (in particular) has been assessed in previous studies20,21,22. In addition, in response to concerns regarding associations between thromboembolic outcomes and COVID-19 vaccines12,13,15,23,24, we investigated additional haematological outcomes in this study (see Table S1). [...] Muthukumar, A. et al. In-depth evaluation of a case of presumed myocarditis after the second dose of COVID-19 MRNA vaccine. Circulation144, 487–498 (2021). [...] Le Vu, S. et al. Age and sex-specific risks of myocarditis and pericarditis following Covid-19 messenger RNA vaccines. Nat. Commun.13, 3633 (2022).