Table 1. Differentiation between COVID-19 myocarditis and COVID-19 VRM.
| Timing | Incidence | Severity and prognosis | Possible mechanism | |
|---|---|---|---|---|
| COVID-19 myocarditis | During the course of a COVID-19 infection, often during the acute phase of illness | • 150/100,000 by US CDC11) | • Survival: 30–80% | • Direct viral invasion |
| • 1,000 to 4,000/100,000 by US VAERS | • Can vary in severity and may be associated with more severe COVID-19 cases | • Immune reaction | ||
| • Endothelial dysfunction secondary to infection of adjacent cells or increased inflammation | ||||
| • Genetic susceptibility | ||||
| COVID-19 VRM | A few days to weeks after receiving a COVID-19 vaccine | • 0.3–5.0/100,000 vaccinated people | • Survival: >99% | • Immune response |
| • Depending on the vaccine platform, age, and sex | • Generally mild and self-limiting, with most individuals recovering fully with appropriate medical care | • Sex-related factor | ||
| • Predominantly in males aged 12 to 40 years | • Rarely, fulminant cases needing ICU care, or transplantation | • Genetic susceptibility |
CDC = Center for Disease Control and Prevention; COVID-19 = coronavirus disease 2019; ICU = intensive care unit; VAERS = Vaccine Adverse Event Reporting System; VRM = vaccine-related myocarditis.