Myopericarditis following COVID-19 vaccination in children: a systematic review and meta-analysis

Abstract

Background: Myopericarditis is a rare but serious COVID-19 vaccine-related adverse event primarily affecting adolescents. Given recent approvals for childhood vaccination, we performed a meta-analysis investigating myopericarditis following mRNA COVID-19 vaccination in children aged <19 years, its overall risk, and high-risk subgroups. Method(s): We searched MEDLINE via Pubmed, Embase, and Scopus from inception to 1 August 2022. We included observational studies reporting myopericarditis in temporal relation to paediatric COVID-19 vaccination. We conducted random-effects meta-analyses (DerSimonianand Laird) on myopericarditis (primary outcome), myocarditis, and pericarditis (secondary outcomes). Result(s): Of 2115 studies, we included 12 (59,229,160 doses). 19.8 (95%-CI: 10.4-37.6) myopericarditis cases were reported per million doses in children, compared to 23.7 (95%-CI: 12.2-46.1) in adults (8 studies, 376,899,888 doses, p=0.70). Compared to the second dose (34.4, 95%-CI: 15.2-77.8), the number of cases post-first dose was significantly lower (9.1, 95%-CI: 4.4-18.8, p=0.017), while case numbers post-third dose was not higher than the second (28.4, 95%-CI: 10.4-61.8, p=0.57; global p=0.031). Males were at higher risk of myopericarditis (67.4, 95%-CI: 36.5-124.5) than females (6.9, 95%-CI: 3.1-15.3, p<0.0001). Finally, the number of cases was higher (overall p<0.0001) amongst children >=12 years (39.9, 95%-CI: 24.1 to 66.0) than children <12 years (3.0, 95%-CI: 2.3 to 3.9). Conclusion(s): Our meta-analysis showed 19.8 cases of myopericarditis per million doses amongst children, not significantly different from adults. Among children, higher risk subgroups include adolescents, males, and second vaccine dose.