The CDC's Advisory Committee on Immunization Practices will hold an emergency meeting June 18 to discuss a potential link between heart inflammation and mRNA COVID-19 vaccines.
During a June 10 presentation to the FDA's advisory panel, the CDC committee said it has received 275 reported cases of myocarditis, heart muscle inflammation, or pericarditis, inflammation of the heart muscle lining, in people ages 16-24 after their second dose of Pfizer or Moderna's vaccine, CNBC reports. The number of cases is higher than the 10 to 102 cases of the conditions scientists anticipated in that age group.
"We clearly have an imbalance here," Tom Shimabukuro, MD, who works in the CDC's Immunization Safety Office, said during the June 10 meeting.
A total of 475 cases of heart inflammation conditions have been reported to the CDC in people age 30 and younger. Most people have fully recovered from their symptoms, CNBC reported.
The findings are preliminary, and scientists are still working to determine whether there is causal relationship between the heart inflammation conditions and mRNA vaccines.
"We're still learning about the rates of myocarditis and pericarditis," Dr. Shimabukuro told The Washington Post.. "As we gather more information, we'll begin to get a better idea of the post-vaccination rates and hopefully be able to get more detailed information by age group."
In May, the CDC said it was investigating "relatively few" reports of myocarditis among teenagers and young adults who were vaccinated against COVID-19. Cases were mostly mild, seemed to occur predominantly in males, typically a few days after vaccination, and appeared to be more common after the second dose than the first.
"We remain confident that the benefits of vaccination far exceed the very small, rare risks," the American Heart Association said in a May 23 statement after the CDC's initial announcement that it was looking into the cases. "The risks of vaccination are also far smaller than the risks of COVID-19 infection itself."