Accelerating Evidence-Informed Vaccine Introductions: Lessons from the Hexavalent Early Adopters Workshop.

Background/Objectives: Transitions to new vaccines or antigen schedules represent complex system changes requiring coordinated governance, reliable data systems, domestic financing, and multisectoral collaboration. In 2025, African countries were moving toward a switch from separate pentavalent and inactivated poliovirus vaccines to the combined hexavalent vaccine. This project report describes the Hexavalent Vaccine Switch Early Adopters Workshop in Dakar, Senegal, which included ten African countries, and its implications for future vaccine introductions. Methods: We conducted a practice analysis drawing on structured documentation of plenary presentations, country case studies, interactive problem-solving sessions, and national roadmap exercises. A thematic framework aligned to ten process points for the hexa switch guided synthesis. Results: Countries reported shared system vulnerabilities, including coexistence risks of legacy and new vaccine stocks, inconsistent data completeness, under-resourced vaccine safety surveillance, and financing uncertainties. Early adopter countries demonstrated operational feasibility, logistical efficiencies, and opportunities for reducing injection burden. Outputs included a Health System Adaptation Checklist, a Switch Risk Mitigation Catalog, and 12-month national roadmaps. Conclusions: Regional peer-learning mechanisms can accelerate decision-making, improve operational quality, and strengthen accountability for vaccine introductions. Structured cross-country collaborations can transform a product switch into a scalable system-strengthening opportunity.