Progress in Immunization Safety Monitoring - Worldwide, 2010-2019.

High levels of coverage with safe and effective immunizations are critical to the successful control and prevention of vaccine-preventable diseases worldwide. In addition to stringent standards to regulate the safety of vaccines, robust postlicensure monitoring systems help ensure that the benefits of vaccines continue to outweigh the risks for the populations who receive them. National Expanded Programmes on Immunization (EPI) are typically responsible for identifying and investigating adverse events following immunization (AEFI), including assessment of causality. National regulatory authorities (NRAs) are mandated to perform postlicensure surveillance of adverse drug reactions, including those associated with receipt of vaccines. This report describes global progress toward meeting World Health Organization (WHO) indicators on minimal country capacity for vaccine safety surveillance and coordination of AEFI reporting between countries' EPI and NRAs. In 2019, among 194 countries, 129 (66.5%) reported having an operational national AEFI causality review committee, compared with 94 (48.5%) in 2010. During 2010-2019, the proportion of countries reporting ≥10 AEFI per 100,000 surviving infants per year (an indicator of country capacity to monitor immunization safety) increased, from 41.2% to 56.2%. In 2019, however, only 46 (23.7%) countries reported AEFI data from both EPI and NRAs. Although global progress has been made toward strengthening systems for vaccine safety monitoring over the past decade, new indicators for monitoring global immunization safety performance are needed to better reflect program functionality. Continued global efforts will be vital to address barriers to routine reporting of AEFI, build national capacity for AEFI investigation and data management, and improve sharing of AEFI data at national, regional, and global levels.