Covid-19 vaccines: safety surveillance manual - Monitoring and responding to adverse events following immunization

Overview

In the context of COVID-19 vaccination, surveillance systems need to be prepared for identifying and responding to both adverse events following immunization (AEFIs) and adverse events of special interest (AESIs) as well as other safety events that may cause public concern, including incidents of substandard or counterfeit vaccines.

AEFIs and AESIs can be detected through passive and active surveillance, respectively. However, if countries do not implement active surveillance for AESIs, all AESI-like adverse events occurring following COVID-19 immunization should be considered as AEFIs and the standard procedure for AEFI response, should be adopted.