Reporting rates of myocarditis and pericarditis (inflammation of the heart or membrane around the heart) following vaccination are very stable. We will continue to monitor and review these adverse effects and will communicate any updated safety advice if needed.Myocarditis is reported in around 1-2 in every 100,000 people who receive Comirnaty (Pfizer), around 2 in every 100,000 of those who receive Spikevax (Moderna) and around 4 in every 100,000 people who receive Nuvaxovid (Novavax). Detailed information about our analysis of myocarditis and pericarditis following vaccination with an mRNA vaccine or Nuvaxovid (Novavax) is available in a previous vaccine safety report.
