Another Study Finds Risk of Heart Inflammation After Pfizer COVID-19 Vaccination

Most cases of post-vaccination myocarditis and pericarditis were found among adolescents between 12 and 17 years old

Syringes and vials of the Pfizer-BioNTech COVID-19 vaccine are prepared to be administered at a drive-up vaccination site in Reno, Nev., on Dec. 17, 2020. Patrick T. Fallon/AFP via Getty Images

The risk of certain heart complications “significantly increased” after Pfizer’s mRNA COVID-19 shots, according to a new study from Thailand.

The peer-reviewed study, published in the Vaccine journal on Jan. 20, looked at the incidence of myocarditis and pericarditis within 30 days of COVID-19 vaccination among 5- to 40-year-olds. Myocarditis is inflammation of the heart muscle called the myocardium, while pericarditis refers to the swelling and irritation of the pericardium, a thin sac-like tissue that surrounds the heart.