Myopericarditis after messenger RNA Coronavirus Disease 2019 Vaccination in Adolescents 12 to 18 Years of Age

J Pediatr. 2021 Nov;238:26-32.e1. doi: 10.1016/j.jpeds.2021.07.044. Epub 2021 Jul 30.


Objectives: To characterize the clinical course and outcomes of children 12-18 years of age who developed probable myopericarditis after vaccination with the Pfizer-BioNTech (BNT162b2) coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccine.

Study design: A cross-sectional study of 25 children, aged 12-18 years, diagnosed with probable myopericarditis after COVID-19 mRNA vaccination as per the Centers for Disease Control and Prevention criteria for myopericarditis at 8 US centers between May 10, 2021, and June 20, 2021. We retrospectively collected the following data: demographics, severe acute respiratory syndrome coronavirus 2 virus detection or serologic testing, clinical manifestations, laboratory test results, imaging study results, treatment, and time to resolutions of symptoms.

Results: Most (88%) cases followed the second dose of vaccine, and chest pain (100%) was the most common presenting symptom. Patients came to medical attention a median of 2 days (range, <1-20 days) after receipt of Pfizer mRNA COVID-19 vaccination. All adolescents had an elevated plasma troponin concentration. Echocardiographic abnormalities were infrequent, and 92% showed normal cardiac function at presentation. However, cardiac magnetic resonance imaging, obtained in 16 patients (64%), revealed that 15 (94%) had late gadolinium enhancement consistent with myopericarditis. Most were treated with ibuprofen or an equivalent nonsteroidal anti-inflammatory drug for symptomatic relief. One patient was given a corticosteroid orally after the initial administration of ibuprofen or an nonsteroidal anti-inflammatory drug; 2 patients also received intravenous immune globulin. Symptom resolution was observed within 7 days in all patients.

Conclusions: Our data suggest that symptoms owing to myopericarditis after the mRNA COVID-19 vaccination tend to be mild and transient. Approximately two-thirds of patients underwent cardiac magnetic resonance imaging, which revealed evidence of myocardial inflammation despite a lack of echocardiographic abnormalities.

Keywords: mRNA COVID-19 vaccine; myocarditis; pericarditis.

Publication types

  • Multicenter Study

MeSH terms

  • Adolescent
  • COVID-19 / epidemiology
  • COVID-19 / genetics
  • COVID-19 / prevention & control*
  • COVID-19 Vaccines / adverse effects
  • COVID-19 Vaccines / genetics*
  • Child
  • Cross-Sectional Studies
  • Female
  • Humans
  • Incidence
  • Magnetic Resonance Imaging, Cine / methods*
  • Male
  • Myocarditis / diagnosis
  • Myocarditis / epidemiology
  • Myocarditis / etiology*
  • Pandemics
  • Retrospective Studies
  • SARS-CoV-2 / immunology*
  • United States / epidemiology
  • Vaccination / adverse effects*
  • Vaccines, Synthetic / adverse effects*


  • COVID-19 Vaccines
  • Vaccines, Synthetic
  • mRNA Vaccine