Clinical Considerations: Myocarditis and Pericarditis after Receipt of COVID-19 Vaccines Among Adolescents and Young Adults

Background

Cases of myocarditis and pericarditis have rarely been observed after COVID-19 vaccination in the United States and evidence from multiple vaccine safety monitoring systems in the United States and around the globe supports a causal association between mRNA COVID-19 vaccines (i.e., Moderna or Pfizer-BioNTech) and myocarditis and pericarditis.

Myocarditis is inflammation of the heart muscle and pericarditis is inflammation of the lining outside the heart; myopericarditis is when both myocarditis and pericarditis occur at the same time.  In these conditions, inflammation occurs in response to an infection or some other trigger. CDC has published case definitions for myocarditis and pericarditis.

Though cases of myocarditis and pericarditis are rare, when cases have occurred, they have most frequently been seen in adolescent and young adult males within 7 days after receiving the second dose of an mRNA COVID-19 vaccine; however, cases have also been observed in females, in other age groups, and after other doses.

The severity of myocarditis and pericarditis cases can vary; most patients with myocarditis after mRNA COVID-19 vaccination have experienced resolution of symptoms by hospital discharge. CDC has published studies with clinical information about myocarditis and pericarditis after COVID-19 vaccination.

Data from the clinical trials of the Novavax COVID-19 vaccine and post-authorization vaccine safety monitoring outside the United States suggest an increased risk of myocarditis and pericarditis following Novavax vaccination.

Guidance for Clinicians

• Report all cases of myocarditis and pericarditis after COVID-19 vaccination to the Vaccine Adverse Event Reporting System (VAERS).
• Consider myocarditis and pericarditis in persons with acute chest pain, shortness of breath, or palpitations, particularly in adolescents and young adults. Younger children who have myocarditis or pericarditis may have non-specific symptoms such as irritability, vomiting, poor feeding, tachypnea (fast breathing), or lethargy.
• Ask about prior COVID-19 vaccination if you identify these symptoms, as well as relevant questions about medical, travel, and social history.
• For initial evaluation, consider an electrocardiogram (ECG), troponin level, and inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate. In the setting of normal ECG, troponin, and inflammatory markers, myocarditis or pericarditis are unlikely.
• For suspected cases, consider consultation with cardiology specialists for assistance with cardiac evaluation and management. Evaluation and management may vary depending on the patient age, clinical presentation, potential causes, or practice preference of the provider.
• For follow-up of patients with myocarditis, consult the guidance from the American Heart Association and American College of Cardiology.
• It is important to evaluate patients to rule out other potential causes of myocarditis and pericarditis. Consider consultation with infectious disease and/or rheumatology specialists to assist in this evaluation.
  • Where available, evaluate for potential causes of myocarditis and pericarditis, particularly acute COVID-19 illness, current SARS-CoV-2 infection (such as PCR testing), as well as other viral causes (such as, enterovirus PCR and comprehensive respiratory viral pathogen testing).
• COVID-19 vaccination is recommended for everyone ages 6 months and older in the United States for the prevention of COVID-19. CDC recommends that people stay up to date with COVID-19 vaccination.
• If myocarditis or pericarditis is diagnosed after a COVID-19 vaccine dose, before giving additional doses, please refer to the latest guidance in the COVID-19 and myocarditis and pericarditis section of the Interim Clinical Considerations for Use of COVID-19 Vaccines web page.