Evidence from multiple safety monitoring systems in multiple countries supports the finding of an increased risk of myocarditis and myopericarditis following mRNA COVID-19 vaccination*
• Risk:
‒ Highest in adolescents and young adults
‒ Males > females
‒ Following dose 2 > dose 1
• Onset clusters within a few days of vaccination, mostly within a week
• Cases have tended to be clinically mild