CDC advisers to meet on heart inflammation link to COVID-19 shots

U.S. public health advisers will meet to discuss a potential link between COVID-19 shots that use messenger RNA technology and heart inflammation after hundreds of vaccinated people experienced a condition called myocarditis.

The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices will gather on June 18 to discuss an increase in reported cases of the condition, particularly among adolescents and young adults. COVID-19 vaccines made by Moderna Inc. and partners Pfizer Inc. and BioNTech SE’s use mRNA technology.

Since April, the CDC has seen a spike in reports of myocarditis along with pericarditis, an inflammation of the membrane around the heart. The cases, while rare, have occurred mostly in male teens and young adults.

The CDC has identified a total of 216 cases of heart inflammation after the first dose of an mRNA shot, and another 573 cases after the second dose. The median age of people with myocarditis or pericarditis following the first dose was 30, and 24 among the second-dose cases. There were 475 cases identified among those under the age of 30.

Most patients have responded well to treatment and rest, according to the agency, and more than 8 in 10 have had full relief from their symptoms. The agency is further examining the cases by age.

About 130 million Americans have received the full two-dose regimen of one of the two authorized mRNA vaccines. Many teenagers have now received their first dose of the Pfizer-BioNTech vaccine, which was cleared for adolescents 12 and older on May 10.

“We’re still learning about the rates of myocarditis and pericarditis,” Tom Shimabukuro, a safety expert of CDC’s National Center for Emerging and Zoonotic Infectious Diseases, said Thursday in a Food and Drug Administration panel meeting. “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.”

Shimabukuro said the U.S. data are consistent with findings from Israel’s vaccinated population.