Comparative assessment of myocarditis and pericarditis reporting rates related to mRNA COVID-19 vaccines in Europe and the United States

ABSTRACT

Objectives

The novel mRNA vaccines proved to be safe and effective in averting severe COVID-19. Vaccine-related complications recorded by pharmacovigilance systems, such as ‘EudraVigilance’ in Europe and ‘VAERS’ in the United States (US), rarely include myocarditis and pericarditis. Given the novelty of the platform and the increasing global-scale vaccine production needs, we assessed their reporting rates comparatively across continents.

Methods

Data of myocarditis and pericarditis cases post COVID-19 vaccination reported from week 52/2020 (December 21 to 27, 2020) to week 40/2021 (October 4 to 10, 2021) were collected for mRNA vaccines from EudraVigilance and VAERS. The corresponding administered vaccine doses were used as denominators to estimate reporting rates for comparison purposes. Cross-tabulation analysis was employed to compare the reporting rates of mRNA vaccines-associated myocarditis and pericarditis between EudraVigilance and VAERS.

Results

Low reporting rates of myocarditis (7.64/million vaccine doses) and pericarditis (5.32/million) were found, with higher rates of both disorders in EudraVigilance compared to VAERS; these differences were more pronounced post-mRNA-1273 (5-6-fold, p=0.000 for myocarditis and p<0.001 for pericarditis) than post-BNT162b2 vaccination (1.5-2-fold, p<0.001 for both conditions). Most myocarditis cases occurred in males <30 years. Pericarditis affected predominantly males <40 and both sexes >40 years. The extremely rare fatalities related to myocarditis (0.102/million) or pericarditis (0.017/million) were also higher in EudraVigilance versus VAERS.

Conclusions

Understanding the underlying causes of the observed differences could provide guidance for the enhanced quality of mRNA vaccines that would also foster vaccine acceptance.

KEYWORDS:

• BNT162b2
• coronavirus disease 2019 (COVID-19)
• messenger ribonucleic acid (mRNA) vaccines
• mRNA-1273
• myocarditis
• pericarditis

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in, or financial conflict with, the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

A reviewer of this manuscript has disclosed that they are a paid consultant to Pfizer and J&J for consulting on research unrelated to COVID vaccine (cardiovascular prevention) and receive funding to my institution from J&J for research. Peer reviewers of this manuscript have no other relevant financial or other relationships to disclose.

Author contributions

Sophia Hatziantoniou: Conceptualization, Data curation, Investigation, Methodology, Writing – original draft, and Writing – review and editing. Cleo Anastassopoulou: Conceptualization, Methodology, Project administration, Supervision, Validation, Writing – original draft, and Writing – review and editing. George Lazaros: Conceptualization, Methodology, Supervision, Validation, and Writing – review and editing. Konstantinos Vasileiou: Statistical analysis and Writing – review and editing. Costas Tsioufis: Conceptualization, Validation, and Writing – review and editing. Athanasios Tsakris: Conceptualization, Funding acquisition, Resources, Supervision, and Writing – review and editing.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14760584.2022.2100765

Additional information

Funding

This paper was not funded.