Myocarditis after BNT162b2 Vaccination in Israeli Adolescents

This observational study analyzed the incidence and clinical outcomes of myocarditis in adolescents (ages 12–15) following BNT162b2 mRNA vaccination in Israel. Among 182,605 vaccinated individuals between June and November 2021, nine cases of probable or definite myocarditis were identified (incidence: 4.8 per 100,000; 95% CI: 1.7–7.9), with eight occurring after the second dose. All cases were mild and presented with hemodynamic stability, elevated cardiac and inflammatory markers, and abnormal ECG findings in 67% of patients. The median hospital stay was three days, with normal ejection fraction in most cases and transient pericardial effusion in four. Echocardiographic follow-up showed resolution of abnormalities, and cardiac MRI revealed minimal late gadolinium enhancement (0–2%). At a median of 206 days post-discharge, all patients were alive without readmission, supporting a favorable long-term prognosis. The study concludes that myocarditis post-vaccination in adolescents is rare, predominantly affects males, and typically resolves without long-term sequelae.

This observational study analyzed the incidence and clinical outcomes of myocarditis in adolescents (ages 12–15) following BNT162b2 mRNA vaccination in Israel. Among 182,605 vaccinated individuals between June and November 2021, nine cases of probable or definite myocarditis were identified (incidence: 4.8 per 100,000; 95% CI: 1.7–7.9), with eight occurring after the second dose. All cases were mild and presented with hemodynamic stability, elevated cardiac and inflammatory markers, and abnormal ECG findings in 67% of patients. The median hospital stay was three days, with normal ejection fraction in most cases and transient pericardial effusion in four. Echocardiographic follow-up showed resolution of abnormalities, and cardiac MRI revealed minimal late gadolinium enhancement (0–2%). At a median of 206 days post-discharge, all patients were alive without readmission, supporting a favorable long-term prognosis. The study concludes that myocarditis post-vaccination in adolescents is rare, predominantly affects males, and typically resolves without long-term sequelae.