Fact Check-Small study of teens is not evidence of long-term heart damage after COVID shots

Social media users have been misinterpreting a small study of nine teenagers in Turkey, and wrongly saying it proves that there is a risk of long-term heart damage after COVID vaccinations.

According to the study, published in the journal Infectious Diseases in Dec. 2022, seven out of seven teens who had been diagnosed with heart inflammation following COVID-19 vaccination showed one possible sign of lingering heart-muscle damage in MRI images three-to-six months later.

But the author of the study said the results may not represent what happens in all teens with post-vaccine heart inflammation, much less all teens who get vaccinated.

Some social media posts misleadingly suggesting the study showed that all vaccine-related myocarditis causes long-term heart damage can be seen (here and here). Reuters contacted James Cintolo, the author of an article quoted in these posts, but did not receive a response.

At least one Twitter user confused the findings of the study even further, taking them to mean: “100% of children who have been injected with MRNA are experiencing heart damage” here .

Myocarditis and pericarditis have been recognized as side effects of mRNA COVID-19 vaccines, particularly among young males. However, cases are rare and the majority are brief and mild (here).

The Turkish study (here) has been “misinterpreted,” its lead author told Reuters.

Dr. Seval Ozen, a pediatric infection specialist at Ankara City Hospital, and colleagues looked at nine male patients aged 14-17, who had a diagnosis of myopericarditis after BNT162b2 mRNA vaccination and were followed up at the pediatric infectious diseases and pediatric cardiology departments at Ankara City Hospital between Sept. 2021 and Mar. 2022.

Ozen said the study performed cardiac magnetic resonance imaging (MRI) on each patient’s first admission, with control MRIs performed on seven of them three to six months later. It observed that late gadolinium enhancement (LGE), which indicates damage of cardiac tissue, was present in the seven patients who had follow up MRIs (two of the nine patients had only the initial MRI).

However, the prognostic implications of these results required further study, Ozen said. “There is no exact causality between these cases and vaccination.”

The case study also did not include pre-vaccination MRIs, so it is not known if any individuals had pre-existing heart damage.

Moreover, the study does not suggest what proportion of teens in the general population experience heart inflammation following vaccination, Ozen told Reuters. “Because of the low number of our cases, we are unable to report the precise incidence of myocarditis and [pericarditis] after mRNA-based COVID-19 vaccination.”

Therefore, he said, it is “not fair” to infer from the study that “100% of kids with vaccine-induced myocarditis had damaged hearts at 3-6 month follow up.”

Ozen added that, according to available scientific literature and observation, COVID-19 infection itself carries higher risks of myopericarditis than the vaccine.

Reuters previously addressed another misrepresented case study of heart effects in teens post-vaccination (here).


Misleading. A case study of nine teenagers with myopericarditis after mRNA COVID-19 vaccination does not explain what caused MRI signs of heart-muscle damage in seven boys, or how often the condition occurs after myocarditis or vaccination in general.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here .