Myocarditis Following Immunization With mRNA COVID-19 Vaccines in Members of the US Military

Abstract

Myocarditis is a heterogeneous disease with diverse clinical patterns, etiologies, and therapeutic responses, reflecting inflammatory injury to myocardial tissue in the absence of ischemia.¹ While viral infections, now including SARS-CoV-2, are the most common triggers of the disease, some myocarditis cases are associated with certain drugs and vaccine exposures.¹ With the exception of cases following live-attenuated smallpox vaccine in the military population,² myocarditis as an adverse event following immunization is described in rare published case reports and infrequent submissions to the Vaccine Adverse Events Reporting System (VAERS).^3,4