Report from the World Health Organization's Immunization and Vaccines-related Implementation Research Advisory...

Serving as the World Health Organization's (WHO) key advisory body for independently reviewing research that assesses the impact and value of vaccines, particularly using transmission and economic modeling analyses, the Immunization and Vaccines-related Implementation Research Advisory Committee (IVIR-AC) gathered for its second semi-annual meeting of 2025 from 1 to 5 September and complemented by ad hoc sessions on 8-10 July. IVIR-AC provided feedback and recommendations across eleven key sessions. This report summarizes the discussions and outcomes of the meeting. Topics covered included leveraging implementation research in WHO African region, Immunization Agenda 2030 (IA2030) impact modeling, subnational immunization coverage estimates for priority countries, modeling diphtheria-tetanus-and-pertussis burden and vaccination strategies, guidance to translate modeling to support evidence-informed decision-making for immunization, multi-model comparisons for typhoid conjugate vaccine schedules, novel metrics to value combination vaccines, stockpiling and vaccination strategies for Ebola response, malaria multi-model comparison of prioritized interventions, additional seasonal doses of malaria vaccine, and 3-dose vs 4-dose malaria vaccine schedule in perennial settings.