Fulminant myocarditis after the first dose of mRNA-1273 vaccination in a patient with previous COVID-19: a case report

BACKGROUND: COVID-19 vaccines have shown success in protecting people worldwide, although serious adverse effects have been reported in very rare cases. CASE SUMMARY: A 32-year-old male with a prior medical history of mild COVID-19 infection developed fulminant myocarditis five days after mRNA-1273 vaccination (first dose), which was confirmed using endomyocardial biopsy. He acutely developed respiratory failure and cardiogenic shock with ventricular tachycardia, but recovered completely with short-term high-dose steroid therapy and mechanical cardiac support, which is the recommended treatment for fulminant lymphocytic myocarditis. DISCUSSION: COVID-19 vaccine-induced myocarditis varies from mild to severe. In the present case, the patient was treated as for fulminant lymphocytic myocarditis and recovered relatively quickly. The mechanism of COVID-19 vaccine-associated myocarditis needs to be urgently investigated.