Evidence links COVID vaccines to heart problem in young people

June 11, 2021 – Swelling of the heart appears to be a very rare side effect that primarily strikes young people after COVID-19 vaccination, a CDC expert reported Thursday, detailing data on cases of myocarditis and pericarditis found through a government security system.

The side effect appears to be more common in adolescents and young men than in older adults and women and can occur in 16 cases per 1 million people given a second dose, said Tom Shimabukuro, MD, deputy director. CDC Immunization Safety. Office, which presented case information to a panel of experts advising the FDA on vaccines.

Witness symptoms include chest pain, shortness of breath and fever.

William Schaffner, MD, an infectious disease specialist at Vanderbilt University in Nashville, believes certain characteristics point to a “rare, but real” signal. First, the events cluster together and occur in the days following vaccination. Second, they tend to be more common in men and young people. Third, he says, the number of events is higher than the so-called “background rate” – the cases one would expect in this age group even without vaccination.

“I don’t think we’re there yet. We haven’t tied a ribbon around it, but I think the data points to that,” he said.

The issue of myocarditis weighed heavily on the Vaccines and the Related Biologics Advisory Committee’s considerations on the type and amount of data that might be needed to green light the use of a COVID vaccine in children.

Because hospitalization rates for COVID are low in children, some have felt that the FDA should require at least a year of study of the vaccines in clinical trials, the amount of data typically required for full approval, instead of the 2 months currently required for emergency use authorization. Others questioned whether the risks of vaccination, however small, might outweigh the benefits in this age group.

“I don’t really see this as an emergency in children,” said committee member Michael Kurilla, MD, director of clinical innovation at the National Institutes of Health. Kurilla, however, said he believed an expanded access program for high-risk children might make sense.

Most of the young adults who suffered from myocarditis recovered quickly, although three needed intensive care and rehabilitation after their episodes. Of the cases with known outcomes, 81% have improved and 19% still have persistent symptoms.