[Analysis of the surveillance system for adverse events following Immunization (AEFI) related to COVID-19 vaccines in Colombia, 2021-2023Análise do sistema de vigilância de ESAVI por vacinas contra a COVID-19 na Colômbia, 2021-2023].

Objective: To describe the functioning of the surveillance system for adverse events following immunization (AEFI) in Colombia using the evaluation tools proposed by the World Health Organization (WHO).

Method: Descriptive study of the performance of the AEFI surveillance system for COVID-19 vaccines between 17 February 2021 and 30 September 2023. WHO indicators for structure, process, and results were adapted. Qualitative information was obtained from official documents and technical consultations, while quantitative data were obtained from VigiFlow and from the Integrated Social Protection Information System.

Results: In its capacity as the regulatory authority, the National Institute for Drug and Food Surveillance (INVIMA) collaborated with the Ministry of Health and Social Protection and the National Institute of Health in the pharmacovigilance of COVID-19 vaccines. Expert committees were established at the national and subnational levels to evaluate AEFI. VigiFlow was implemented for case reporting and management, training was promoted, and signs and regulatory actions were detected, based on Pan American Health Organization (PAHO) and WHO protocols. Information on AEFI was disseminated through bulletins. Technical cooperation between INVIMA and PAHO was strengthened.

Conclusions: The AEFI surveillance indicators for COVID-19 were met. The regulations and functions of the health authorities provided a solid basis for vaccine pharmacovigilance activities, allowing effective use of technical resources. A regulatory framework for non-COVID-19 vaccines, continuous training, and greater automation is needed in order to improve the capacity of the vaccine safety program.