Heart Problems After Vaccination Are Very Rare, Federal Researchers Say

More than 1,200 cases have been reported, mostly mild and more often in young men and boys. The benefits of vaccination still far outweigh the risks, experts said.

By Apoorva Mandavilli

The coronavirus vaccines made by Pfizer-BioNTech and Moderna may have caused heart problems in more than 1,200 Americans, including about 500 who were younger than age 30, according to data reported on Wednesday by researchers at the Centers for Disease Control and Prevention.

Still, the benefits of immunization greatly outweighed the risks, and advisers to the C.D.C. strongly recommended vaccination for all Americans 12 and older.

The heart problems reported are myocarditis, an inflammation of the heart muscle; and pericarditis, inflammation of the lining around the heart. The risk is higher after the second dose of an mRNA vaccine than after the first, the researchers reported, and much higher in men than in women.

But overall, the side effect is very uncommon — just 12.6 cases per million second doses administered. The researchers estimated that out of a million second doses given to boys ages 12 to 17, the vaccines might cause a maximum of 70 myocarditis cases, but would prevent 5,700 infections, 2,215 hospitalizations and two deaths.

Agency researchers presented the data to members of the Advisory Committee on Immunization Practices, which makes recommendations on vaccine use in the United States. (The scientists grouped pericarditis with myocarditis for reporting purposes.)

Most cases were mild, with symptoms like fatigue, chest pain and disturbances in heart rhythm that quickly cleared up, the researchers said. Of the 484 cases reported in Americans under age 30, the C.D.C. has definitively linked 323 cases to vaccination. The rest remain under investigation.

“These events are really very rare, extremely rare,” said Dr. Brian Feingold, an expert on heart inflammation in children at the UPMC Children’s Hospital of Pittsburgh. “That needs to be taken in context with illness and morbidity and mortality related to Covid.”

Source: Read Full Article