The risk of heart-related complications like myocarditis and pericarditis after receiving the COVID-19 vaccine is a real, though very small, risk. But before you let that deter you from the vaccine, learn who is at the highest risk, and how that compares to the complications of contracting the coronavirus.

Vaccine status has quickly become common conversation: Are you vaccinated? Which one did you have? What about a booster?

Given the state of the world and the impact of the pandemic, it's not all that surprising. And the vaccine conversation (er, debate?) is not likely to slow down. Just recently, the CDC released new data about the effectiveness of vaccines against COVID-19 and the delta variant. Turns out, unvaccinated Americans are about six times more likely to get the coronavirus compared to fully vaccinated Americans.

"COVID-19 is a serious illness. Although it infects us through the lungs and primarily involves inflammation in the lungs, it can cause systemic complications that affect the heart, [as well as] other major organs," says Donald M. Lloyd-Jones, M.D., Sc.M., FAHA, American Heart Association volunteer president and an epidemiologist and chair of the department of preventive medicine at Northwestern University Feinberg School of Medicine in Chicago. "We see evidence of inflammation in the heart (myocarditis) and other organs in part because of blood clots—[and those blood clots] are happening as a result of the high levels of systemic inflammation caused by the virus."

There is also a risk of heart problems like myocarditis after receiving the vaccine. "Some vaccine recipients have developed the rare heart-related complication called myocarditis or heart inflammation a few days after receiving a COVID-19 vaccine manufactured by Pfizer-BioNTech or Moderna," explains Lloyd-Jones.

But before you let that hesitation sink in too deep—or maybe even deter you from considering the vaccine—there are a few things you should know.

a COVID-19 vaccine bottle floating on a designed background
Credit: Getty Images / Basilico Studio Stock / Yevgen Romanenko

Myocarditis and Pericarditis Risk Is Highest in Those Infected with COVID

First, the risk of developing a heart condition—like myocarditis or pericarditis—as a result of the COVID-19 vaccine is actually much lower than the risk of having those same heart problems if you get COVID-19. (Myocarditis is an inflammation of the heart muscle, and pericarditis is an inflammation of the outer layer that surrounds the heart.) A study published in September 2021 in the New England Journal of Medicine, compared it well. Researchers found that in people aged 16 years and older:

  • There were an extra 2.7 cases of myocarditis for every 100,000 people in the vaccinated group, compared to the unvaccinated group. Myocarditis in the general population is quite rare.
  • There were an extra 11 cases of the condition for every 100,000 people who had been infected with the coronavirus, compared with those who had not gotten COVID-19.

In another recent study, this one in children under 16 years old, the comparison wasn't as direct. But still, researchers found the risk of myocarditis in kids with COVID-19 was 37 times higher compared to kids who didn't have coronavirus.

Heart-Related Complications after Vaccination Are Likelier for Some People, Not Everyone

Second, the risk of developing a heart complication isn't elevated for everyone, but is likelier in some specific groups (i.e., maybe not you). "There have been reports of rare, yet well publicized, heart-related concerns among adolescents and young adults—and more likely males than females," says Lloyd-Jones. More specifically, the risk of developing myocarditis or pericarditis is higher in males between 12 and 49 years old (with the highest risk in the 12- to 29-year-old range) and females between 12 and 29 years old. This past summer the American Academy of Pediatrics reported an estimated 39 to 47 cases of myocarditis per 1 million vaccinations given in males 12 to 29 years old.

Other Vaccines Up Your Risk, Too

Third, other vaccines are also associated with a slight risk of developing heart-related complications. For instance, a study published in January 2021 in the journal Vaccine looked at reports of myopericarditis (an inflammation of both the heart and surrounding membrane) after other vaccines, such as those for smallpox, anthrax, hepatitis B and even some flu strains. Researchers concluded that the risk of developing myopericarditis was most common after a smallpox vaccine and also more common in males. And the overall risk—much like after the COVID-19 vaccine—was quite low for these other vaccines.

Is There a Bottom Line?

Overall, the benefits of the vaccine outweigh the risks, which you've probably heard before. Heart and stroke patients are—as you might expect—at higher risk for serious complications, including death, from COVID-19. So are folks with obesity, high blood pressure and diabetes.

But research now also indicates that anyone who gets COVID-19 may be more likely to experience heart-related issues. A study published in July 2021 in The Lancet reported that people who had COVID-19 had a threefold higher risk of heart attack and stroke in the first two weeks following their illness.

"We also know that complications from getting the infection can last many months," says Lloyd-Jones. "In the vast majority of people who have developed myocarditis after receiving the vaccine, it has been a short-term, self-limited issue with no evidence of significant heart damage or longer-term complications to date."

Also, let's not lose sight of the fact that hundreds of millions of people in the United States have received COVID-19 vaccines under the most intense safety monitoring in U.S. history. And statistically only a relative handful have experienced complications. Also, those complications—from a scientific standpoint—are associations (not correlations). Meaning we can't say yet (because we don't know for certain) that the vaccine caused myocarditis or pericarditis. "Myocarditis is usually the result of a viral infection, and, while it seems likely, it is yet to be determined if these cases have any correlation to receiving a COVID-19 vaccine," says Lloyd-Jones.

If You're Worried, Here's What to Look For

It's always wise to monitor yourself, and your loved ones, after any immunization. When it comes to heart-related complications, such as myocarditis and pericarditis, after a coronavirus vaccine, here's what you should know.

  • Symptoms typically set in within the first week, sometimes as soon as two days afterward
  • It more commonly occurs after the second vaccine dose
  • Both myocarditis and pericarditis have these symptoms: chest pain, shortness of breath, feelings of having a fast-beating, fluttering or pounding heart. Seek medical care if these symptoms appear, especially within a week of the vaccine, advises the CDC.

The situation surrounding COVID-19 continues to change quickly; it's possible that information or data has changed since publication. While EatingWell is trying to keep our stories as up-to-date as possible, we also encourage readers to stay informed on news and recommendations by using the CDCWHO and their local public health department as resources.