Researchers at Oxford University evaluated over one million English children aged 5 to 11 and adolescents aged 12 to 15 for incidents of myocarditis and pericarditis in relation to the COVID-19 infection and the COVID-19 vaccine.According to the preprint, myocarditis and pericarditis only occur after vaccination and not after COVID-19 infection.“Whilst rare, all myocarditis and pericarditis events during the study period occurred in vaccinated individuals,” the authors wrote.