Myocarditis and pericarditis can occur in COVID-19 vaccinated individuals, according to a study conducted by Oxford University researchers.

The researched published a preprint of a study that compared the health outcomes in children and adolescents who were received a COVID-19 vaccination verses children who were not vaccinated. 

“Whilst rare, all myocarditis and pericarditis events during the study period occurred in vaccinated individuals,” the authors of the study wrote. 

Health data from more than 1 million British children from age 5 to 11 and adolescents aged 12 to 15 were part of the study. 

"Among both adolescents and children, myocarditis and pericarditis were documented only in the vaccinated groups, with rates of 27 and 10 cases/million after first and second doses respectively," according to the preprint.