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Yes, there have been reports of heart inflammation in adolescents after COVID-19 vaccination, but cause not yet known

The CDC says there have been “relatively few reports of myocarditis,” mainly in adolescents and young adults. But the vaccines have not been identified as the cause.
Credit: Khunatorn - stock.adobe.com

UPDATE (2/23/22): In an update published Feb. 22, the Centers for Disease Control and Prevention (CDC) said a longer interval of time between the two initial doses of the Pfizer and Moderna COVID-19 vaccines could be optimal for some people over the age of 12, especially males between the ages of 12 to 39 years old.

Extending the interval between the first and second dose to eight weeks might reduce the risk of myocarditis, according to the CDC. While rare, the CDC says the relative risk for myocarditis is higher in males ages 12 to 39.

A shorter interval -- three weeks for Pfizer and four weeks for Moderna -- between the first and second doses remains the recommended interval for people who are moderately to severely immunocompromised, adults ages 65 years and older, and others who need rapid protection due to increased concern about community transmission or risk of severe disease.


UPDATE (8/11/21): A later analysis found mild heart inflammation conditions were reported at a higher prevalence than expected among some people who received the two-dose mRNA vaccines, according to the American Heart Association. Most patients were discharged from the hospital as their symptoms returned to normal with or without treatment and the AHA continues to say the benefits of COVID-19 vaccination outweigh the risks of this rare condition. The CDC recommends you seek medical care if you experience chest pain, shortness of breath or feelings of a fast-beating heart within a week of your COVID-19 vaccination. The original story remains as published below:


The Centers for Disease Control and Prevention (CDC) on May 12 recommended children 12 to 15 years old get the Pfizer COVID-19 vaccine. About 17% of children ages 12 to 15 in the United States have received the first dose of the vaccine, according to the CDC.

As more children in that age group get vaccinated against COVID-19, more information is being gathered about the side effects adolescents are experiencing.


VERIFY viewer Kathy asked: Is it true that adolescents who get the COVID-19 vaccine are having heart problems?



This needs context.

Yes, there have been reports of adolescents and young adults having heart inflammation after getting an mRNA COVID-19 vaccine, but it has not been established the vaccines caused the heart inflammation.


The CDC on May 17 published a report from the COVID-19 Vaccine Safety Technical Work Group, a team that reviews COVID-19 vaccine safety data weekly, that concluded there were “relatively few reports of myocarditis” in people who received the COVID-19 mRNA vaccines. The mRNA vaccines that have received emergency use authorization in the United States are the two-dose vaccines developed by Pfizer and Moderna.

VERIFY reached out to the CDC, asking how many reports of myocarditis there have been, but has not heard back. The American Heart Association said the CDC was “reviewing several dozen cases of myocarditis.” The CDC described the number of reports as “rare, given the number of vaccine doses administered, and have been reported after mRNA COVID-19 vaccination (Pfizer-BioNTech and Moderna), particularly in adolescents and young adults.”

The Mayo Clinic describes myocarditis as “an inflammation of the heart muscle.” Dr. Payal Kohli, a practicing cardiologist, said myocarditis can be caused by several different things but that it most commonly occurs from virus infection. She said symptoms include chest pain, shortness of breath, fever, fatigue and swelling in the ankles brought on by problems with the pumping function of the heart.

The CDC report listed more details about who reported suffering from myocarditis after COVID-19 vaccination. Myocarditis was reported more predominantly in adolescents and young adults, more often in males than females, more often after the second dose than after the first dose, and typically within four days after vaccination. Most cases appeared to be mild, the CDC said, and follow-up investigations of the cases are ongoing.

The CDC also noted, “Within CDC safety monitoring systems, rates of myocarditis reports in the window following COVID-19 vaccination have not differed from expected baseline rates.” Kohli said that essentially means the reported cases of myocarditis may have nothing to do with the COVID-19 vaccines.

“It just happened that those people got the vaccination, they would have had the myocarditis anyways, because the rates or the number of cases of myocarditis are the same this year as they were two or three years ago when people weren't getting the vaccinations,” she explained. “So, these are the baseline numbers of cases that we see every year, anyhow.”

The CDC did not say the COVID-19 vaccines caused the reported cases of myocarditis but that the Vaccine Safety Technical Work Group “felt that information about reports of myocarditis should be communicated to providers.”

There has been no temporary pause placed on the mRNA vaccines like there was in April when the CDC and FDA investigated cases of rare blood clots in people who had received the Johnson & Johnson COVID-19 vaccine.

The CDC still recommends everyone 12 and older get a COVID-19 vaccine. The American Heart Association and the American Academy of Pediatrics also still say adolescents should get vaccinated against COVID-19.

Kohli had the following recommendation to parents who may be apprehensive about their child getting a COVID-19 vaccine following the reports of myocarditis.

“So, I would say, first of all, we don't know that this has anything to do with the vaccine, it could just be the background rate and noise,” Kohli said. “Number two, even if it's related to the vaccine, the cases have been mild, and a full recovery is expected. And the benefits of the vaccine to your teenager to get their lives back to normal and protect them are far greater than any potential risks with a small number of cases.”

Kohli said adolescents have been reporting a lot of the same COVID-19 vaccine side effects as adults, from arm pain, to fever, to fatigue. The FDA reported the most common side effects in the Pfizer clinical trials among children ages 12 to 15 were consistent with people 16 and older: pain at the injection site, tiredness, headache, chills, muscle pain, fever and joint pain. The CDC says those side effects are “normal signs” the body is building protection.

More from VERIFY: Yes, vaccinated people can transmit COVID-19 through kissing

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