Compared to vaccination, COVID-19 itself is far more likely to lead to heart problems in teenage boys and young men, the Centers for Disease Control and Prevention reported Friday.
The study is the first to compare directly the odds of a type of heart inflammation called myocarditis following an infection versus vaccination — providing a clearer understanding of the real risk for heart problems and perhaps offering comfort to parents and young men who have had questions about the risks and benefits of the vaccine.
Myocarditis has long been linked to a variety of viruses, including influenza and coxsackieviruses. The condition was identified as a potential side effect of mRNA COVID-19 vaccines in young people last summer.
At that time, the CDC found that myocarditis cases were more than double what would normally be expected among males in their teens and early 20s who had been vaccinated. While both the Moderna and the Pfizer-BioNTech vaccines have been linked to the problem, Pfizer’s shot is the only one authorized for people under age 18.
Most cases of vaccine-related myocarditis got better without any lasting issues, but the reports left many parents concerned, wondering whether the potential heart risks from COVID-19 vaccines in young men are greater than their benefit.
The new data, doctors say, answer that question with a resounding no. It confirms what pediatric cardiologists have long noted in their patients: Heart problems are far more likely to occur as a result of COVID-19 than after the vaccines.
“It absolutely mirrors what we’ve seen here,” Dr. Gerard Boyle, medical director of the Pediatric Heart Failure and Transplant Services at Cleveland Clinic Children’s Hospital, said of the new findings.
“The number of patients that have come in with post-infection myocarditis have been much more numerous than the patients that have come in with post-vaccination myocarditis — without question,” he said.
In the study, researchers analyzed electronic health records of more than 15 million people in 40 health care systems nationwide, collected from January 2021 through the end of January 2022, looking for evidence of heart inflammation or multisystem inflammatory syndrome in children. MIS-C causes inflammation around several organs, including the heart.
Overall, heart problems related to either the infection or the vaccines were rare.
Rates of vaccine-related myocarditis, though uncommon, were highest for boys, ages 12 to 17, particularly after their second dose of vaccine.