COVID-19 Vaccination Benefits Outweigh Risks of Heart Inflammation, CDC Says

vaccine and variants

Ellen Lindner / Verywell

Key Takeaways

  • In rare cases, Pfizer's and Moderna's COVID-19 vaccines have triggered myocarditis, or heart inflammation, typically in males under 30. Most reported cases have been mild and people have recovered from the condition.
  • The FDA will update the COVID-19 vaccine fact sheets to include a warning about risk of heart inflammation.
  • The CDC's vaccine advisers said the benefits of COVID-19 vaccinations still far outweigh the risks.

U.S. health officials are working quickly to add a warning about rare cases of heart inflammation to the fact sheets for COVID-19 vaccines. 

A Centers for Disease Control and Prevention (CDC) panel on Wednesday acknowledged a likely association between the COVID-19 vaccines and rare cases of myocarditis or pericarditis in adolescents and young adults, but officials say the benefits of vaccination still outweigh the risks.

What Is Myocarditis?

Myocarditis is the inflammation of the myocardium, which is the heart muscle.

“[Myocarditis] has been around for a while. Traditionally, there have been thought to have viral triggers, although there can be others,” Matthew Oster, MD, a member of the CDC COVID-19 Vaccine Task Force said during the meeting. “It does appear that mRNA vaccine may be a new trigger for myocarditis, yet it does have some different characteristics in the presentation and particularly the course of how patients are doing.”

There have been over 1,200 reports of post-vaccination myocarditis or pericarditis reported to the Vaccine Adverse Event Reporting System (VAERS), according to the Wednesday presentation by CDC’s Advisory Committee on Immunization Practices (ACIP). Data shows that a majority of people affected are men and boys under 30. In reported cases, symptoms typically surfaced within one week of a vaccination, most commonly after the second dose.

VAERS myocarditis

Centers for Disease Control and Prevention

CDC officials are gathering more data to fully understand the potential risks, how to manage it and whether there are any long-term issues.

What Is Pericarditis?

Pericarditis is a condition in which the pericardium (the protective elastic sac that encloses the heart), becomes inflamed.

“If you’re a month or so out from your vaccination, feel pretty reassured that this is not a side effect you’re going to have,” Jenifer Haythe, MD, a cardiologist at Columbia University Medical Centers, tells Verywell.

Haythe adds that outside factors, including viruses like COVID-19, can contribute to myocarditis, particularly around this time of year. Coxsackievirus is one example that circulates in the early summer and has the potential to trigger myocarditis. 

“I would be surprised if the CDC decided to halt the vaccine in this age group,” Haythe says. “But it's certainly something that doctors, parents, and people should be on the lookout for.”

Some warning signs include sharp chest pains especially when sitting forward, shortness of breath, heart palpitations, and arrhythmia, she adds.

CDC advisers also offered guidance on COVID-19 vaccinations for people with or with histories of pericarditis:

  • People who develop myocarditis after their first dose of COVID-19 are encouraged to consult a doctor or family member for more information before seeking a second dose. 
  • People who develop pericarditis after their first dose are encouraged to wait until the condition resolves. Once recovered, they may seek out a second dose of any FDA-approved COVID-19 vaccine.
  • Those with a history of pericarditis or myocarditis prior to receiving any COVID-19 vaccine are encouraged to get any FDA-approved COVID-19 vaccine.

After Wednesday’s meeting, the CDC safety group will work with the Food and Drug Administration (FDA) to finalize wording for warnings on the fact sheets for Pfizer’s and Moderna’s COVID-19 vaccines.

“I just remind my patients that myocarditis can happen anyway, even without COVID around, or a COVID vaccine around,” Haythe says. “It's a very small risk, and COVID-19 also carries a risk of developing myocarditis. I still would recommend people to get the vaccine.”

What This Means For You

A small number of people who received the COVID-19 vaccine experienced heart inflammation days after their shot. Health authorities will add a warning about the condition to the vaccine data sheets, but still strongly encourage people 12 and older to be vaccinated against COVID-19.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

By Claire Wolters
Claire Wolters is a staff reporter covering health news for Verywell. She is most passionate about stories that cover real issues and spark change.