Objective
To describe the implementation and pioneering work of a vaccine pharmacovigilance committee in the state of São Paulo, Brazil, for the analysis of events supposedly attributable to vaccination or immunization (ESAVI) during the COVID-19 pandemic.
Methods
This is a retrospective, mixed-methods (qualitative and quantitative) case study focusing on the work carried out by the pharmacovigilance committee in the years 2021 and 2022. The minutes of committee meetings were used to describe how the committee operates. ESAVI cases discussed and addressed at expert meetings were recorded. The number of vaccine doses applied during the period of analysis, as well as the number of ESAVIs reported within that period, was obtained from statewide information systems.
Results
Over 55 pharmacovigilance committee meetings held in 2021–2022, 118 ESAVI cases—most related to COVID-19 vaccines—were discussed. A total of 126,778,252 doses of COVID-19 vaccines were administered during this period, with 42,893 ESAVI reported. Among the cases selected for discussion, 71.2% occurred after the first dose of vaccine, 32.8% represented neurological events, and only 5% were deemed to have a causal relationship with the vaccine.
Conclusions
The pharmacovigilance committee played a significant role in the ESAVI surveillance system during the period of analysis by assisting in the evaluation of more complex cases. It shows potential to contribute positively to strengthening the immunization program, especially within the safe vaccination system framework.