key: cord-0862830-52hgkdjb authors: Umei, Tomohiko C.; Kishino, Yoshikazu; Shiraishi, Yasuyuki; Inohara, Taku; Yuasa, Shinsuke; Fukuda, Keiichi title: Recurrence of myopericarditis following mRNA COVID-19 vaccination in a male adolescent date: 2021-12-09 journal: CJC Open DOI: 10.1016/j.cjco.2021.12.002 sha: 531cffc3599dfbe6e47c8f1ae114331cc455c653 doc_id: 862830 cord_uid: 52hgkdjb Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has spread worldwide, resulting in health and economic crises. Vaccination against SARS-CoV-2 infection is considered a valid prevention measure to control this pandemic. There have been reports of cases of myopericarditis following mRNA COVID-19 vaccination. We present a case of a 20-year-old man with recurrent myopericarditis following an initial episode of influenza virus-induced myopericarditis and after receiving a second dose of the mRNA-1273 Moderna COVID-19 vaccine. Careful attention should be paid to patients with a history of myocarditis following COVID-19 vaccination. Coronavirus disease 2019 is caused by severe acute respiratory syndrome 2 coronavirus 2 (SARS-CoV-2). It has spread worldwide, resulting in health and economic 3 crises. Vaccination against SARS-CoV-2 infection is considered a valid prevention 4 measure to control this pandemic. There have been reports of cases of myopericarditis 5 following mRNA COVID-19 vaccination. We present a case of a 20-year-old man with 6 recurrent myopericarditis following an initial episode of influenza virus-induced 7 myopericarditis and after receiving a second dose of the mRNA-1273 Moderna COVID- Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome 2 coronavirus 2 (SARS-CoV-2) that has spread worldwide, resulting in health and 3 economic crises. Vaccination against SARS-CoV-2 is considered a protective approach 4 with more than 95% efficacy to control the COVID-19 pandemic 1 . However, some cases 5 of myopericarditis have recently been reported as complications of mRNA COVID-19 6 vaccination with an incidence of 1 case per 10,000-100,000 inoculations 2 . Although 7 these events are rare, cases were much more common following a second dose, especially 8 in young male adolescents 2 . Herein, we present a case of a 20-year-old male adolescent 9 with recurrent acute myopericarditis five years after an initial episode of acute influenza TTE performed on admission day shows hypokinesis of the anteroseptal wall with no 13 pericardial effusion (A). TTE findings one month after discharge shows an almost normal Safety and Efficacy of the BNT162b2 14 mRNA Covid-19 Vaccine Myocarditis and Pericarditis following COVID