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Risk of Myocarditis and Pericarditis Following BNT162b2 and mRNA-1273 COVID-19 Vaccination
24 Pages Posted: 16 Mar 2022More...
Background: Accumulating evidence indicates that mRNA COVID-19 vaccination is associated with increased risk of myocarditis and possibly pericarditis, especially in young males. It is not yet clear if risk differs between mRNA-1273 (Moderna) versus BNT162b2 (Pfizer-BioNTech).
Methods: Myocarditis and pericarditis cases in patients 18–39-years-old were characterized by medical record review at 8 participating Vaccine Safety Datalink sites. We updated previous risk estimates of myocarditis and pericarditis during days 0–7 (risk interval) versus days 22–42 (comparison interval) post-vaccination and conducted direct comparisons of risk for mRNA-1273 versus BNT162b2 during 0–7 days post-vaccination. Rate ratios (RRs) were estimated by conditional Poisson regression.
Findings: From December 14, 2020–January 15, 2022 there were 41 cases after 2,891,498 doses of BNT162b2 and 38 cases after 1,803,267 doses of mRNA-1273. Cases had similar demographic and clinical characteristics. Most were hospitalized for ≤1 day; none required intensive care. During days 0–7 after dose 2 of BNT162b2, the incidence was 14.3 (CI: 6.5 – 34.9) times higher than the comparison interval, amounting to 22.4 excess cases per million doses; after mRNA-1273 the incidence was 18.8 (CI: 6.7 – 64.9) times higher than the comparison interval, amounting to 31.2 excess cases per million doses. In head-to-head comparisons 0–7 days after either dose, risk was moderately higher after mRNA-1273 than after BNT162b2 (RR: 1.61, CI 1.02 – 2.54).
Interpretation: Both mRNA COVID-19 vaccines were associated with increased risk of myocarditis and pericarditis in 18-39-year-olds. Overall risk estimates were modestly higher after mRNA-1273 than after BNT162b2.
Funding Information: This study was supported by the Centers for Disease Control and Prevention (CDC), contract number Contract #200-2012-53581-0011.
Declaration of Interests: NPK reports research support from Pfizer for COVID-19 vaccine clinical trials and Pfizer, Merck & Co., GlaxoSmithKline, Sanofi Pasteur, and Protein Science (now Sanofi Pasteur) for unrelated studies.
ALN reports research support from Pfizer and Vir Biotechnology for unrelated studies.
WKY reports research support from Pfizer for protocol development in the 17 past.
JGD report research support from Janssen for an unrelated study. None of the other coauthors have disclosures to report.
Ethics Approval Statement: This activity was approved by the Institutional Review Boards of all participating organizations with a waiver of informed consent and was conducted consistent with appliable federal law and CDC policy.
Keywords: VACCINES, myocarditis, vaccine safety, COVID-19, SARS-CoV_2
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