The Massachusetts-based biotech company said it made the conclusion after “carefully reviewing the available safety data to date for Moderna COVID-19 Vaccine for cases of myocarditis and/or pericarditis.”
“The company will continue to closely monitor these reports and is actively working with public health and regulatory authorities to further assess this issue,” it said in a statement.
A spokesperson for the Centers for Disease Control and Prevention did not immediately respond to a request for comment.
A CDC advisory panel is holding an emergency meeting on June 18 to discuss rare, but higher-than-expected, reports of heart inflammation in 16- to 24-year-olds after receiving their second dose of Pfizer‘s or Moderna‘s Covid-19 vaccines.
A CDC official said Thursday that the agency has received reports of 275 cases of myocarditis or pericarditis in that age group as of May 31, higher than the 10 to 102 cases that would be expected. The condition involves inflammation of the heart muscle or the lining around it.
“We clearly have an imbalance there,” Dr. Tom Shimabukuro of the CDC’s Immunization Safety Office said Thursday at a meeting of the FDA’s Vaccines and Related Biological Products Advisory Committee. The group met to discuss safety issues surrounding the use of Covid-19 vaccines in children as young as 6 months old.
The CDC’s vaccine safety group said last month that it was looking into heart inflammation conditions in a “relatively few” people who received Covid vaccinations. Officials say they still don’t know whether the condition is truly related to the vaccines.
Some of the reported cases may be something else other than myocarditis or pericarditis upon further investigation, Shimabukuro said Thursday.
Men make up the majority of the reported cases and most of the cases appear mild, officials say. Of the 270 people who have developed the condition and have been discharged, 81% of them have fully recovered, according to a CDC presentation at the meeting Thursday. As of May 31, 15 people were hospitalized, with three in intensive care, the agency said.
Though no link has been found between the vaccines and the condition, health experts say finding rare side effects once a vaccine or drug is administered to the general population is common. The U.S. has distributed millions of Covid vaccines, which have been helpful in driving down new cases and hospitalizations across the country.