Epoch HealthMyocarditis and Pericarditis Only Appear After COVID Vaccination: NHS Preprint

New research highlights the exclusive occurrence of myocarditis and pericarditis in vaccinated adolescents and children, suggesting a need for reevaluation of COVID-19 vaccination strategies in younger populations while considering broader clinical implications for post-vaccination adverse events.

A recent preprint from Oxford University researchers reveals that myocarditis and pericarditis only occur in children and adolescents following COVID-19 vaccination, not infection. The study, which evaluated more than a million English minors, found that vaccinated adolescents experienced higher incidences of these heart inflammations compared to children. Despite this, vaccinated adolescents had lower chances of COVID-19 infection and severe outcomes than their unvaccinated counterparts.

Key Points:

• Myocarditis and pericarditis were exclusively observed in vaccinated children and adolescents, with no cases reported in unvaccinated individuals during the study period.
• The study included more than 1 million English children aged 5 to 11 and adolescents aged 12 to 15, comparing vaccinated and unvaccinated cohorts.
• Vaccinated adolescents had a significantly lower risk of testing positive for COVID-19 and requiring hospitalization or critical care compared to unvaccinated adolescents.
• Vaccinated children showed no substantial difference in COVID-19 infection rates and hospitalization compared to their unvaccinated peers.
• The study recorded 15 cases of pericarditis and 3 cases of myocarditis among more than 839,000 vaccinated children and adolescents, with all myocarditis cases and most pericarditis cases occurring in adolescents.
• Most myocarditis and pericarditis cases occurred after the first vaccine dose, with more than half requiring hospitalization or emergency care.
• The maximum hospital stay for myocarditis treatment was one day, and there were no fatalities from myocarditis or pericarditis.
• The data contradicts other studies showing higher myocarditis rates post-COVID-19 infection, suggesting potential regional or methodological differences.
• The study utilized NHS England’s OpenSAFELY-TPP database, covering 40% of English primary care practices.
• Adolescents showed more significant benefits from vaccination, with reduced hospitalization rates, while children did not show substantial differences between vaccinated and unvaccinated groups.
• Dr. Peter McCullough, a cardiologist not involved in the study, expressed concerns about the necessity and risks of COVID-19 vaccination for children, citing potential for unpredictable fatal cardiac events.
• The authors observed that COVID-19 hospitalization was more likely than myocarditis or pericarditis in both vaccinated and unvaccinated adolescents.
• For vaccinated adolescents, 33 were hospitalized for COVID-19, while 3 developed myocarditis. In unvaccinated adolescents, 57 were hospitalized.
• Children’s rapid innate immune responses may contribute to their lower severity of COVID-19 outcomes compared to adults.

Overall, among 18‐ to 29‐year olds in the US, an estimated 22.4 excess cases per million after the second dose of Pfizer‐BioNTech® and 31.2 cases per million second doses after Moderna® vaccine developed myocarditis. (European Journal of Heart Failure)

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