What about myocarditis after COVID vaccines?
Here is what the checked sources say. Each title links to the original.
Myocarditis Cases Reported After mRNA-Based COVID-19 Vaccination in the US From December 2020 to August 2021
Reviewed passive-surveillance reports to VAERS after 354 million mRNA COVID-19 doses given December 2020 to August 2021; 1,626 met the myocarditis case definition. These are reporting rates within 7 days of a dose, not a complete count. Rates were highest after the second dose in young males: about 106 per million Pfizer doses in boys 16 to 17, 71 in boys 12 to 15, and 52 to 56 in men 18 to 24. Of 826 patients under 30 with detailed records, 96% were hospitalized and 87% of those had symptoms resolve by discharge. Several authors disclosed maker grants or fees.
Risk of Myocarditis After Sequential Doses of COVID-19 Vaccine and SARS-CoV-2 Infection by Age and Sex
Studied 42.8 million vaccinated people aged 13 and up in England, December 2020 to December 2021. It estimated extra myocarditis hospital admissions or deaths per million people in the 28 days after each dose or a positive COVID-19 test, a different measure from reporting rates. Overall, risk was higher after infection than after vaccination. The exception was men under 40 after a second Moderna dose: about 97 extra cases per million, versus 16 after infection. For women under 40 the extra risk was similar (7 vs 8 per million). Pfizer doses carried a smaller added risk.
Long-Term Prognosis of Patients With Myocarditis Attributed to COVID-19 mRNA Vaccination, SARS-CoV-2 Infection, or Conventional Etiologies
Followed everyone aged 12 to 49 hospitalized for myocarditis in France from late 2020 to mid-2022 for 18 months: 558 after vaccination, 298 after COVID-19 and 3,779 from other causes. A combined outcome of readmission for heart inflammation, other heart events or death occurred in 32 of 558 vaccine-linked patients versus 497 of 3,779 with ordinary myocarditis (standardized hazard ratio 0.55, about 45% lower). This compares hospitalized patients only. Patients, mostly young men, still sometimes needed medical care for several months after discharge.
COVID-19: The Disease & Vaccines
CHOP says a small number of people, mostly males in their teens and 20s, get heart inflammation (myocarditis), usually within 4 days of a second mRNA dose; chest pain or shortness of breath should be checked by a doctor. CHOP says it most commonly goes away in a few days, and that parents should keep watching their children after vaccination. Early in the rollout it was estimated at about 1 in 50,000 people; CHOP says US surveillance found rates similar to background in the 2022 to 2025 seasons. CHOP says infection, overall, causes myocarditis more often. Reviewed August 2025.