A study published Tuesday showed that US military personnel vaccinated against Covid-19 showed higher than expected rates of carditis, although the condition remains extremely rare.
The study found that 23 previously healthy males with an average age of 25 complained of chest pain within four days of receiving a COVID-19 injection. She added that the accident rate was higher than some previous estimates had expected.
All patients who had recovered at the time of the study’s publication or were recovering from myocarditis — an inflammation of the heart muscle — had received shots from Pfizer Inc (PFE.N), BioNTech SE (22UAy.DE), or Moderna Inc (MRNA.O).
Last week, US health regulators added a warning to the literature accompanying mRNA vaccines to point out the rare risk of heart infection seen primarily in young males. But they said the shots’ benefit in preventing COVID-19 still clearly outweighed the risks. Read more
The study, published in the medical journal JAMA Cardiology, said 19 of the patients were current military personnel who received the second dose of the vaccine. The others received a single dose or retired from military service.
The study said general population estimates would have predicted eight or fewer cases of myocarditis among the 436,000 male soldiers who received two shots of COVID-19.
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 males and in the week after the second vaccine dose than would be expected in the general population. A presentation at that meeting found that the heart condition developed at a rate of about 12.6 cases per million people vaccinated.
The study said that eight of the military patients in the study underwent diagnostic tests and showed signs of inflammation in the heart that cannot be explained by other causes. The ages of the patients in the study ranged from 20 to 51.
The CDC began investigating a possible link between mRNA vaccines and myocarditis in April after Israel learned it was studying such cases in people who had received the Pfizer/BioNTech vaccine there, and after a report that the US military had also discovered cases.
Health regulators in many countries are conducting their own investigations.
(Reporting by Carl O’Donnell) Editing by Bill Bercrot
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