A population-based assessment of myocarditis after messenger RNA COVID-19 booster vaccination among adult recipients. (June 2023)

• Record Type: Journal Article
• Authors: Naveed, Zaeema; Li, Julia; Naus, Monika; Velásquez García, Héctor Alexander; Wilton, James; Janjua, Naveed Z.
• Is Part Of: International journal of infectious diseases. Volume 131(2023)
• Page Start: 75
• Page End: 78
• Publication Date: 2023-06
• Subjects: SARS-CoV-2 -- mRNA vaccination -- Myocarditis -- Booster dose; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2023.03.027
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: Myocarditis after messenger RNA (mRNA) COVID-19 vaccination is rare. The myocarditis rate after an mRNA vaccine booster is lower than the second dose. No association detected between mRNA COVID-19 booster vaccine type and myocarditis. Abstract: Objectives: We aimed to estimate the rate of myocarditis after the messenger RNA (mRNA) COVID-19 booster vaccination by vaccine type, age, and sex. Methods: We used data from the British Columbia COVID-19 Cohort, a population-based cohort surveillance platform. The exposure was a booster dose of an mRNA vaccine. The outcome was diagnosis of myocarditis during hospitalization or an emergency department visit within 7-21 days of booster vaccination. Results: The overall rate of myocarditis was lower for the booster dose (6.41, 95% confidence interval [CI]: 3.50-10.75) than the second dose (17.97, 95% CI: 13.78-23.04); (Rate ratiobooster vs dose-2 = 0.34, 95% CI: 0.17-0.61). This difference was more apparent for the mRNA-1273 vaccine type. After the second dose, the myocarditis rate in males was significantly lower for BNT162b2 than mRNA-1273 overall and among those aged 18-39 years. In contrast, after the booster dose, no significant differences between myocarditis and vaccine type was observed overall or within the specific age groups among males or females. Conclusion: Myocarditis after mRNA COVID-19 vaccines is a rare event. A lower absolute risk of myocarditis was observed after a booster dose of mRNA vaccine than the primary series second dose.