Age-specific incidence of acute myocarditis/pericarditis in adolescents following Comirnaty COVID-19 vaccination in Asia is lacking. As such, a study aimed to assess clinical characteristics and incidence of acute myocarditis/pericarditis among Hong Kong adolescents following Comirnaty vaccination. The results appeared in the Journal of Personalized Medicine.

In this population cohort study, researchers assessed 33 Chinese adolescents between 12 and 17 years old who developed acute myocarditis/pericarditis following Comirnaty vaccine between June 14, 2021, and September 4, 2021 (87% male, 12% female). Patients were monitored for adverse events following immunization via a pharmacovigilance system for COVID vaccines.

The results showed that almost 82% of males and about 18% of females developed acute myocarditis/pericarditis after receiving both doses. All cases were mild and required only conservative management, the researchers noted. They observed that the overall incidence of acute myocarditis/pericarditis was 18.52 cases (95% confidence interval [CI], 11.67-29.01) per 100,000 persons vaccinated. The incidence after both doses were 3.37 (95% CI, 1.12-9.51) and 21.22 (95% CI, 13.78-32.28) per 100,000 persons vaccinated, respectively. Among male adolescents, the incidence after both doses was observed to be 5.57 (95% CI, 2.38-12.53) and 37.32 (95% CI, 26.98-51.25) per 100,000 persons vaccinated.

There is a significant increase in the risk of acute myocarditis/pericarditis following Comirnaty vaccination among Chinese male adolescents, especially after the second dose,” the researchers noted.


Keywords: Comirnaty, Hong Kong, Myocarditis, Pericarditis, adolescents