There have been a higher-than-expected number of cases of heart inflammation in 16- to 24-year-olds after receiving their second dose of
Pfizer’s or
Moderna’s Covid-19 vaccines, the Centers for Disease Control and Prevention said Thursday, citing preliminary data from its vaccine safety monitor system.
The CDC has received reports of 275 cases in that age group as of May 31, the agency said in a presentation prepared for a Food and Drug Administration advisory panel meeting Thursday. Scientists expected between 10 and 102 cases of myocarditis or pericarditis — where the heart muscle or the lining surrounding it become inflamed, according to the CDC.
Though rare, there have been a total of 475 reported cases of myocarditis or pericarditis in people age 30 and younger, according to the CDC. Most patients who were hospitalized, or 81% of them, had full recovery from their symptoms, the agency said. As of May 31, 15 people remain hospitalized, with three in intensive care.
The majority of cases appear to occur in men and the median time to the onset of symptoms is two to three days, according to the CDC.
Some of the reported cases may be something else other than myocarditis or pericarditis upon further investigation, Shimabukuro said.
During a panel discussion later Thursday, Dr. Cody Meissner, a member of the committee, said he was “worried” about the heart issue reported in young vaccine recipients. He questioned whether there will be scarring of the muscular tissue or arrhythmia as a result of the condition.
“I think that’s unlikely but we don’t know that,” said Meissner, also a professor of pediatrics at Tufts University School of Medicine. “So, before we start vaccinating millions of adolescents and children, it’s so important to find out what the consequences are.”
The CDC’s vaccine safety group said last month it was looking into heart inflammation conditions in a “relatively few” people who received Covid vaccinations.
The cases were predominantly in adolescents and young adults and usually occurred within four days after getting the shot, the CDC
said at the time. The condition was seen more often in men and most cases appear to be mild, the agency said, though officials are following up with the patients.
Health experts say finding rare side effects once a vaccine or drug is administered to the general population is common and if myocarditis turns out to be related to the Covid vaccine, the risk is negligible when compared with the risks of being infected with Covid-19.
