Innovative approaches

Impact of Innovative Approaches in Monitoring Adverse Events Following Immunization (AEFI)

At the 2020 joint GACVS/ACSoMP meeting, members recommended adopting a new indicator, the rate of case-based serious AEFI reported per 1 000 000 total population of a country or sub-national area in a year to monitor the performance of national AEFI reporting systems. Countries are currently transitioning from the use of the previous indicator (the ratio of 10 reports of adverse events following immunization (AEFI) per 100 000 surviving infants per year) to the new one. The 2023 meeting allowed members to view how the new indicator is being implemented to gauge progress at country and regional levels. Presentations from the WHO European Region and National Centre for Pharmacovigilance (ALIMS) and Institute of Public Health of Serbia (IPH) demonstrated the practical application, progress, and challenges of the use of the indicator. Members were shown how data are now being collected and used to understand the strength and capacity of AEFI reporting systems.

 Specifically, the WHO Regional Office for Europe (EURO) presented 2022 data and showed that 45 out of the 53 Member States (85%) reported any AEFI(s) and serious AEFIs were reported by 41 Member States (81%). Of those Member States that used the new indicator for serious AEFIs, 33 or 62% reported at least one serious AEFI in one million population. Progress stems largely from middle-income countries beginning to report serious AEFIs into the VigiBase system (the WHO Global Database of Individual Case Safety Reports) although they have not reached the target yet. There are various activities ongoing in the region to strengthen vaccine safety monitoring: advancements in global and regional immunization policy and planning are under discussion, AEFI indicators are being incorporated into European immunization agenda monitoring framework, and WHO encourages countries to have a national indicator.

 How countries have been reporting was also reviewed, with 18 countries reporting through VigiBase only, 23 through VigiBase and the Joint Reporting Form on Immunization (JRF), and three reporting through JRF alone. Differentiated by income level: of the four lower- and middle-income countries only one reports through the system; of upper middle-income counties 11 of 15 use VigiBase, and of the 34 high-income countries, 29 report through VigiBase. Also presented was the value of the new (one per one million population) indicator for COVID-19 vaccines, routine vaccines excluding COVID-19 vaccines, and for all vaccines. The median value for lower-income countries was 0.1, for middle-income countries was 0.2, and for high-income countries was 7.3. The overall median for the region was 3.2 per million. Reasons why some countries have not been able to achieve the target include weak pharmacovigilance systems and political sensitivities especially in lower- and middle-income countries, and smaller populations (less than 100 000) in high-income countries. The presentation from ALIMS and IPH described to committee members how countries are adapting to the new indicator and then, submitting the data through VigiFlow, allowing it to be captured in VigiBase.

 GACVS members in general continued to support the use of the new indicator. The committee noted the advances made by countries such as Serbia and asked to see more granular data to enable decision-making including its use for safety signal detection.