The Centers for Disease Control and Prevention has reported that there was a rare but higher-than-average incidence of heart inflammation in young people and teens who received the second Pfizer or Moderna COVID-19 shot.
At a Thursday meeting of the Vaccines and Related Biological Products Advisory Committee, the agency said that as of May 31, it had 275 preliminary reports of myocarditis — inflammation of the heart muscles — among people ages 16 to 24. Though that’s a small fraction of the more than 12 million doses administered to people in this age range, and an even smaller fraction of the nearly 130 million Americans who have been fully vaccinated with either Pfizer or Moderna’s doses, it’s still high: Health officials would typically expect fewer than 100 cases within the same group.
The agency has yet to confirm a link between the shots and myocarditis and will hold an advisory panel on June 18 to discuss it. Tom Shimabukuro, a CDC vaccine-safety official, cautioned that some of these reports may not represent true cases of the condition. “It’s a bit of an apples-to-oranges comparison because, again, these are preliminary reports,” Shimabukuro said, according to CBS News. “Not all these will turn out to be true myocarditis or pericarditis reports.”
If a link to the vaccine is found, then work turns to figuring out who is most susceptible and how to prevent it. Thankfully, the vast majority of myocarditis cases seen after vaccination have been mild and responded well to anti-inflammatory medications; in more than eight in ten of the cases identified by the CDC, sufferers experienced full relief from their symptoms, Bloomberg reports.
The CDC’s announcement comes after the Israeli Ministry of Health’s finding of “a possible link between the second vaccine dose and the onset of myocarditis among young men aged 16 to 30.”
Still, U.S. health officials say the benefits of COVID-19 vaccination outweigh the known and potential risks. “At this point, the risk benefit still favors vaccination certainly in this age group,” former FDA commissioner Dr. Scott Gottlieb told CNBC on Friday. “That’s what CDC and FDA have also affirmed.”