Up to 1 in 27 of the vaccinated people in the study showed levels associated with subclinical myocarditis, the British website Daily Sceptic reported.
A Thai study published in August found elevated troponin levels or cardiac symptoms after COVID vaccination indicative of myocarditis or pericarditis in seven (3.5%) of 200 boys.
A study published in January by the Journal of the American Medical Association based on data from the CDC's Vaccine and Adverse Events Reporting System, or VAERS, found 1,991 reports of myocarditis after receipt of at least one shot and 684 separate reports of pericarditis.
In September, the CDC's analysis of its own Vaccine Safety Datalink surveillance data showed the incidence of myocarditis after vaccination is three to five times higher for young men than what the agency was reporting at that time last year