[Experiences and Challenges of the Ecuadorean National Advisory Commission on Serious Events Supposedly Attributable to Vaccination or Immunization, 2020-2023Experiências e desafios da Comissão Consultiva Nacional sobre Eventos Supostamente Atribuíveis à Vacinação ou Imunização graves do Equador, 2020-2023].

Objective: To describe the experiences of the National Advisory Commission on Serious Events Supposedly Attributable to Vaccination or Immunization (ESAVI) implemented in Ecuador for the period 2020-2023. Methods: A report analyzing the implementation, operations, and results of the National Advisory Commission on Serious ESAVI in Ecuador was prepared. A quantitative analysis of vaccination records was carried out, as well as a qualitative analysis based on expert interviews, reflecting the direct experiences and operational challenges faced by the members of the Commission. Results: Implementation of the Commission has allowed for the systematic recording and analysis of serious ESAVIs. Of 256 reported cases, 139 were analyzed: 59% were considered coincident events; 16.6%, unclassifiable; 6.5%, indeterminate; 5%, stress-related; 3.6% as events related to a programmatic error; and 9.4% as vaccine-related, which included allergic reactions, Guillain-Barré syndrome, and thrombosis, among others. The experts highlighted the need to improve staff training and technology infrastructure, and noted that the Commission played a crucial role in monitoring vaccine safety, as well as in increasing public confidence in vaccination processes. Conclusions: The National Advisory Commission has played an essential role in vaccine safety surveillance in Ecuador by ensuring reporting, causality analysis, and investigation of serious ESAVIs. Challenges were identified and will need to be addressed to maintain public trust in immunization programs.