Transient Cardiac Injury in Adolescents Receiving the BNT162b2 mRNA COVID-19 Vaccine.

Background Vaccines are paramount in the effort to end the coronavirus disease 2019 global epidemic. BNT162b2 is approved for the vaccination of adolescents over 16 years of age. Systemic adverse events were scarce though the pretested cohort of this age group was relatively small. The aim of the current study is to raise awareness for potential adverse reactions. Methods This is a case series of patients diagnosed with perimyocarditis following vaccination. Patients were compiled from 3 pediatric medical centers in Israel through a network of pediatricians and data regarding those cases was collected. In addition, incidence of perimyocarditis during the vaccination period was compared with previous years. Results All patients were males 16-18 years old, of Jewish descent, who presented with chest pain that began 1-3 days following vaccination (mean, 2.1 days). In 6 of the 7 patients, symptoms began following the 2nd dose and in 1 patient following the 1st dose. All cases were mild and none required cardiovascular or respiratory support. The incidence of perimyocarditis during the vaccination period was elevated in comparison to previous years. Conclusions This case series describes a time association between coronavirus disease 2019 vaccine and perimyocarditis in adolescents. All cases were mild, although only long-term follow-up can reveal the true impact of this cardiac injury. While it seems that the incidence of perimyocarditis during the vaccination campaign period is increased, a more comprehensive data collection on a wider scale should be done. We hope this report will serve as a reminder to report events and allow for analysis of potential adverse reactions.