COVID-19 vaccines associated with vasovagal malaise: A retrospective study in two mass vaccination centers and analysis of the WHO pharmacovigilance database.

The association between COVID-19 vaccines and vasovagal malaise (VVM) has recently been reported in the literature. Our study aimed to describe COVID-19 vaccines associated VVM cases and to identify risk factors of COVID-19 vaccines associated VVM. To this end, we performed a descriptive study of VVM reports associated with COVID-19 vaccines from two French mass COVID-19 vaccination centers. We also extracted reports of VVM associated with all-COVID-19 vaccines in VigiBase®, the World Health Organization (WHO) pharmacovigilance database to analyze demographic data. In the two French mass vaccination center database, 408 entries reported VVM after the standard administration of tozinameran - Pfizer® (1.63/1,000 vaccinated persons). Of these cases, 213 (52.2%) occurred in women, and 193 (47.3%) occurred in the 18-29 year-old (yo) age group. In 232 cases (56.8%), patients had a history of anxiety related to needles or medical visits, 213 (52.2%) reported a fear of COVID-19 vaccination in particular, and 233 (57.1%) had a history of VVM. In VigiBase®, 336,291 notifications of COVID-19 vaccines associated with VVM were identified in the adult population during the period of analysis. The most reported age class was 18-44 years (52.4%), and women represented 71.7% of the reports. Reporting widely differed depending on the country. This study, performed in real-life conditions, highlights that VVM is associated with all-COVID-19 vaccines. Young age and history of anxiety related in young adults could be a triggering factor of vaccines-associated VVM. Further studies are needed to confirm our results.