Long-term trends in reporting of cardiac adverse drug reactions to COVID-19 vaccines - an exploratory analysis of the EudraVigilance database.

BACKGROUND: Vaccination against COVID-19 could be followed by a serious cardiac adverse drug reaction (SCADR), which is a noxious, unintended response to the administered vaccine and is life-threatening, usually requires hospitalisation and may result in death. We aimed to explore long-term trends in reporting of SCADRs to COVID-19 vaccines. METHODS: In this retrospective, longitudinal, observational study, suspected (potentially linked to vaccination) SCADRs to Comirnaty (Pfizer BioNTech), Spikevax (Moderna), Vaxzevria (AstraZeneca) and Jcovden (Janssen) vaccines were extracted from the EudraVigilance database (n = 87,000). This data was coupled with the corresponding weekly number of administered vaccine doses from the Vaccine Tracker database (n = 733,837,251). RESULTS: The most frequently documented categories of SCADRs included arrhythmia (n = 29,936), thrombosis (n = 21,381), inflammation (myocarditis and pericarditis, n = 13,421), blood pressure abnormalities (n = 10,535) and syncopes (n = 10,363), both during the first year and for the whole vaccination period. During the first year of vaccine distribution, the total number of SCADRs per million administered vaccine doses was 77.3 (Comirnaty), 76.4 (Spikevax), 115.3 (Jcovden) and 230.3 (Vaxzevria). These values changed significantly when the whole period of vaccinations was considered (145.6, 146.3, 203.5, 320.5, respectively; p < 0.001). Concerning vaccine administration timelines, the reporting of suspected adverse drug reactions appears to be more widely distributed over time (p < 0.05). CONCLUSIONS: The frequency of reporting suspected SCADRs after COVID-19 vaccinations appears to change dynamically over time. Concerning the administration of vaccine doses, the reporting of potential post-vaccination ADRs seems to be more distributed in time. These observations suggest that post-approval long-term monitoring of suspected ADRs may be valuable for improving data capture and supporting vaccine safety assessment. This underlines the potential importance of comprehensive surveillance in the context of infectious diseases and vaccine development programs.