June 25, 2022Open Access

Age and sex-specific risks of myocarditis and pericarditis following Covid-19 messenger RNA vaccines

Q: What is the clinical evidence from this study?

Study design: Case-Control. Population: Myocarditis and pericarditis (n=35475). Intervention: Covid-19 mRNA vaccines (BNT162b2 and mRNA-1273) vs. Unexposed (no vaccination or vaccination >21 days prior). Primary outcome: Myocarditis within 7 days following the second dose of mRNA-1273 vaccine (OR 30, 95% CI 21-43).

Key Result

Covid-19 mRNA vaccines were associated with increased risks of myocarditis during the first week following the second dose, with adjusted odds ratios of 8.1 for BNT162b2 and 30 for mRNA-1273.

Study Design

Type

Case-Control (n=35,475)

Structured PICO

Does COVID-19 mRNA vaccination increase the risk of hospital admission for myocarditis or pericarditis in persons aged 12 to 50 years?

Population

32 million persons aged 12 to 50 years in France. The study analyzed 1,612 cases of myocarditis and 1,613 cases of pericarditis, matched to 16,120 and 16,130 control subjects respectively.

Intervention

BNT162b2 or mRNA-1273 vaccine, first or second dose, administered 1 to 7 days prior to index date.

Comparator

Unexposed individuals (no vaccination or vaccinated more than 21 days prior to index date), matched by age, gender, and area of residence.

Outcome

Hospital admission with a diagnosis of myocarditis or pericarditis.safety

COVID-19 mRNA vaccines are associated with a significantly increased risk of myocarditis and pericarditis within the first week after vaccination, particularly following the second dose of the mRNA-1273 vaccine in young males.

Main Result

Effect estimate: OR 30 (95% CI 21-43)

Limitations

Lack of clinical and laboratory information in the National Health Data System
Cases identified solely on diagnosis codes, potentially missing asymptomatic or mild forms
Could not investigate potential long-term consequences
Did not study the Covid-19 booster vaccination
Associations across age and sex subgroups could not always be quantified with certainty due to limited time span

Abstract

Cases of myocarditis and pericarditis have been reported following the receipt of Covid-19 mRNA vaccines. As vaccination campaigns are still to be extended, we aimed to provide a comprehensive assessment of the association, by vaccine and across sex and age groups. Using nationwide hospital discharge and vaccine data, we analysed all 1612 cases of myocarditis and 1613 cases of pericarditis that occurred in France in the period from May 12, 2021 to October 31, 2021. We perform matched case-control studies and find increased risks of myocarditis and pericarditis during the first week following vaccination, and particularly after the second dose, with adjusted odds ratios of myocarditis of 8.1 (95% confidence interval CI, 6.7 to 9.9) for the BNT162b2 and 30 (95% CI, 21 to 43) for the mRNA-1273 vaccine. The largest associations are observed for myocarditis following mRNA-1273 vaccination in persons aged 18 to 24 years. Estimates of excess cases attributable to vaccination also reveal a substantial burden of both myocarditis and pericarditis across other age groups and in both males and females.

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Cite This Study

Vu et al. (Sat,) conducted a case-control in Myocarditis and pericarditis (n=35,475). Covid-19 mRNA vaccines (BNT162b2 and mRNA-1273) vs. Unexposed (no vaccination or vaccination >21 days prior) was evaluated on Myocarditis within 7 days following the second dose of mRNA-1273 vaccine (OR 30, 95% CI 21-43). Covid-19 mRNA vaccines were associated with increased risks of myocarditis during the first week following the second dose, with adjusted odds ratios of 8.1 for BNT162b2 and 30 for mRNA-1273.

synapsesocial.com/papers/6a19bbdc1d4d911c80ea8b4a https://doi.org/https://doi.org/10.1038/s41467-022-31401-5