June 29 (Reuters) – Members of the U.S. military who have been vaccinated against COVID-19 have shown higher-than-expected rates of heart inflammation, although the disease is still extremely rare, according to a study released Tuesday.
The study found that 23 previously healthy men, averaging 25 years old, complained of chest pain within four days of receiving an injection of COVID-19. The incident rate was higher than some previous estimates would have predicted, he said.
All patients who, at the time of the study’s publication, had recovered or were recovering from myocarditis – an inflammation of the heart muscle – had received injections from Pfizer Inc (PFE.N) and BioNTech SE ( 22UAy.DE) or Moderna Inc (MRNA.O).
U.S. health regulators last week added a warning to the literature accompanying these mRNA vaccines to point out the rare risk of heart inflammation seen primarily in young men. But they said the advantage of gunfire in preventing COVID-19 clearly continues to outweigh the risk. Read more
The study, which was published in the medical journal JAMA Cardiology, indicated that 19 of the patients were current military personnel who had received their second dose of the vaccine. The rest had received a dose or had retired from the military.
General population estimates would have predicted eight or fewer cases of myocarditis in the 436,000 male service members who received two COVID-19 injections, the study found.
An external panel of experts advising the US Centers for Disease Control and Prevention (CDC) said last week that reports of myocarditis were higher in men and in the week after the second dose of the vaccine than what would be expected in the general population. A presentation at that meeting revealed that heart disease has emerged at a rate of about 12.6 cases per million people vaccinated.
Eight of the military patients in the study received diagnostic tests and showed signs of heart inflammation that could not be explained by other causes, according to the study. The patients in the study were between 20 and 51 years old.
The CDC began investigating the potential link between mRNA vaccines and myocarditis in April after Israel reported it was investigating such cases in people who received the Pfizer / BioNTech vaccine there, and after a report that the US military had also found cases.
Health regulators in several countries are conducting their own investigations.
Reporting by Carl O’Donnell Editing by Bill Berkrot
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