ABSTRACT
Background: There are some concerns about the cost/benefit ratio of Covid-19 vaccination in children and young adolescents age due to the greater response to immune stimulation. Myocarditis is a feared adverse event (AE). Method(s): On January 4, 2022 we searched the Pubmed and EMBASE datasets for population studies assessing myocarditis events in pediatric subjects, and US nationwide data about COVID-19 vaccinations and AEs. Result(s): The studies selected (n=10) were highly heterogeneous, and did not include subjects <12 years. The estimated incidence of myocarditis in the US was 2.80 over 100,000 in fully vaccinated individuals (i.e., receiving two doses of mRNA vaccines or received one dose of a single-dose vaccine) aged 6-17 years. No events were reported <5 years (n=9,985). The incidence of myocarditis was 1.05 over 100,000 in those aged 18-64 years, and 2.75 over 1,000,000 >=65 years. The incidence of fatal or lifethreatening myocarditis was 3.78 over 1,000,000 6-17 years, 1.78 over 1,000,000 18-64 years, and 8.54 over 10,000,000 >=65 years, with the same order of magnitude than the odds of being struck by lightning. The incidence of COVID-19 myocarditis is 1.33 in 1000 <16 years, i.e., 47.5-fold higher than fully vaccinated individuals. Conclusion(s): The reported incidence of myocarditis in subjects aged >=12 years is slightly higher in males and after the second dose, but extremely low. No case of myocarditis <5 years were reported in the US. In fully vaccinated individuals aged 6-17 years, the estimated incidence of myocarditis was far lower than the risk of COVID-19 myocarditis. (Figure Presented).
ABSTRACT
Background and Aim: There are some concerns about the cost/ben-efit ratio of Covid-19 vaccination in the pediatric age due to the greater response to immune stimulation in children and young adolescents. Myocarditis is a feared adverse event (AE). Method(s): On January 4, 2022 we searched the Pubmed and EMBASE datasets for population studies assessing myocarditis events in pediatric subjects, and the US nationwide data about COVID-19 vaccinations and AEs. Result(s): The studies selected (n = 10) were highly heterogeneous, and did not include subjects lt;12 years. In a nationwide study the incidence of myocarditis was 1.34 over 100,000 in males and 7 over 1,000,000 in females aged 16-19 years after the first dose, and 1.51 over 10,000 in males and 4.6 over 1,000,000 in females after the second dose. All studies with available data reported a higher risk in males and after the second dose. Based on US data, the estimated incidence of myocarditis was 2.80 over 100,000 in fully vaccinated individuals (i.e., receiving two doses of mRNA vaccines or received one dose of a single-dose vaccine) aged 6-17 years. No events were reported in subjects lt;5 years (n = 9,985). The incidence of myocarditis was 1.05 over 100,000 in those aged 18-64 years, and 2.75 over 1,000,000 >=65 years. The incidence of fatal or life-threatening myocarditis was 3.78 over 1,000,000 6-17 years, 1.78 over 1,000,000 18-64 years, and 8.54 over 10,000,000 >=65 years, with the same order of mag-nitude than the odds of being struck by lightning (around 2 over 1,000,000). The incidence of COVID-19 myocarditis is 1.33 in 1000 lt;16 years, i.e., 47.5-fold higher than fully vaccinated individuals. Conclusion(s): The reported incidence of myocarditis in subjects aged >=12 years is slightly higher in males and after the second dose, but extremely low. No case of myocarditis lt;5 years were reported in the US. In fully vaccinated individuals aged 6-17 years, the esti-mated incidence of myocarditis was 2.80 over 100,000, and of fatal or life-threatening myocarditis 3.78 over 1,000,000, with the same order of magnitude than being struck by lightning, and far lower than the risk of COVID-19 myocarditis.