Study: 7 US teens report heart inflammation after second Pfizer dose

Seven U.S. male teenagers reported heart muscle inflammation after their second dose of the Pfizer-BioNTech vaccine, according to a study released on Friday, suggesting a “possible” but unproven link between the condition and the vaccine.

The research, published in the journal Pediatrics, highlighted seven cases of teenagers between 14 and 19 who developed symptoms for myocarditis days after receiving their second dose in April and May. 

All reported chest pain within four days of the second shot, resolved their symptoms “rapidly” and were sent home from the hospital after two to six days.

The study is among the latest reports of young men developing symptoms of myocarditis after getting the Pfizer-BioNTech vaccine, although the report emphasized that “no definite causal relationship” has been proven and such cases “appear rare.”

“No causal relationship between vaccine administration and myocarditis has been established,” the study said. 

Doctors determined none of the seven teenagers had multisystem inflammatory syndrome in children, and only one tested positive for antibodies, indicating a possible prior COVID-19 infection. 

As of May 23, more than 1.5 million people under the age of 18 had received both doses of the Pfizer-BioNTech vaccine, the only vaccine available to minors in the U.S. Out of those, more than 650,000 got their second dose more than two weeks ago, the study reported, citing Centers for Disease Control and Prevention (CDC) data. 

“We urge physicians and healthcare providers to consider myocarditis in the evaluation of adolescents and young adults who develop chest pain after COVID-19 vaccination,” the study said. “All cases of myocarditis in patients with recent COVID-19 vaccination should be reported promptly to” the federal government’s Vaccine Adverse Event Reporting System.

Experts are now examining whether there are more cases of myocarditis after vaccination than are typical, though the CDC recommends that those older than 12 still get vaccinated, warning that the risks of COVID-19 are greater than the shot.

An editorial posted in Pediatrics with the article noted that the heart inflammation cases need to be examined but noted that “the benefits of vaccination against this deadly and highly transmissible disease clearly far outweigh any potential risks.”

The CDC has documented more than 3.3 million COVID-19 cases and more than 400 deaths among children under 18 years old.

Pfizer told The Hill in a statement that it was aware of the “rare reports” of heart inflammation among primarily male adolescents and young adults after receiving the companies’ vaccination.

The company said it does not comment on non-Pfizer studies but said “we actively monitor all adverse events from our studies and available vaccines.” 

Israel’s Ministry of Health reported a “possible link” between the Pfizer-BioNTech vaccine and cases of heart inflammation, with 148 out of the 275 cases reported between December and May occurring “around the time of vaccination.”

The CDC declared last month that it was studying the “relatively few” cases of myocarditis in young people who got the vaccine.