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Myopericarditis After COVID-19 Vaccine Low Among Teens and Young Adults

Feb 16, 2023
group of students gathering during pandemic

Parents thinking about getting their children vaccinated against COVID-19 may have been scared when they heard that heart inflammation might be a side effect. People wondered how often it happens, how dangerous it is, and what the long-term effects could be.

With information from more than 20 studies in our recent publication in JAMA Pediatrics, we found that myopericarditis, a type of heart inflammation, didn’t happen very often; when it did, most adolescents and young adults recovered and have not had major short-term issues so far.

What is Myopericarditis?

Myopericarditis is a combination of myocarditis (inflammation, swelling, and injury of the heart muscle) and pericarditis (inflammation of the sac covering around the heart).

Myopericarditis can occur after viral infections and has been shown to occur more frequently after COVID-19 infection than after COVID-19 vaccination. Common symptoms are chest pain, abnormal or irregular heartbeat, and difficulty catching your breath.

While most cases are mild, more severe cases can result in serious illness and require hospitalization. There is no specific treatment and cases improve on their own with rest and supportive care. If a physician has diagnosed myocarditis, it is important to refrain from competitive sports and intense activities until the heart is recovered.

Who Did We Study?

We looked at studies from around the world and then reviewed hundreds of patients between 12 and 20 years old who had no history of myopericarditis or heart disease - most were males around 16 years of age.

How Often Did We Find Myopericarditis?

Myopericarditis after being vaccinated for COVID-19 was extremely rare. Myopericarditis was seen more often after the second COVID-19 vaccine dose, with most kids being diagnosed 2-3 days after vaccination.

Importantly, the risk of developing myocarditis after getting sick with COVID-19 was much higher than after COVID-19 vaccination (11 cases per 100,000 COVID-19 infections compared to 2.7 cases per 100,000 vaccinated people).

What Are the Early Outcomes?

Although 92.6% of patients were hospitalized and a quarter of those required ICU care, most of them just needed to be monitored. Only 1.3% needed additional intensive care or ICU treatment. More importantly, no patients died or needed life support. On average patients had a hospital stay of less than three days.

Are the Benefits of COVID-19 Vaccines Greater than the Risks?

Yes, the benefits of the COVID-19 vaccination greatly outweigh the potential risks. Myopericarditis after COVID-19 vaccination in adolescents and young adults is rare, and the early outcomes are largely favorable.

These data are reassuring but further studies are needed to investigate the long-term outcomes. COVID-19 in youth can also lead to life-threatening inflammatory complications, including multisystem inflammatory syndrome in children (MIS-C), encephalitis, and neuroimmune disorders. These findings could help improve decision-making for parents as well as understanding of myopericarditis after COVID-19 vaccination.

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Featured Expert

Simon Lee, MD
Simon Lee, MD

Dr. Simon Lee is an attending in The Heart Center, director of the Coronary Anomalies Program and co-director of the Kawasaki Disease Program.

Nationwide Children's Researcher
Jun Yasuhara, MD
Cardiovascular Research

Dr. Jun Yasuhara received his MD from Keio University School of Medicine, Japan in 2007. He completed his pediatric residency and pediatric cardiology fellowship at Keio University Hospital, Japan in 2017. He is a board-certified pediatric cardiologist. He underwent a basic research training on cardiovascular development and genetics of congenital heart disease under the mentorship of Dr. Hiroyuki Yamagishi.

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700 Children’s® features the most current pediatric health care information and research from our pediatric experts – physicians and specialists who have seen it all. Many of them are parents and bring a special understanding to what our patients and families experience. If you have a child – or care for a child – 700 Children’s was created especially for you.