Application of the WHO new vaccine introduction prioritisation and sequencing framework to guide evidence-based vaccine introduction decisions in Iran, 2025–2030

OBJECTIVES: To document the first application of the WHO New Vaccine Introduction Prioritization and Sequencing Toolkit (NVI-PST) in the WHO Eastern Mediterranean Region and to describe how Iran's National Immunization Technical Advisory Group (NITAG) adapted and implemented the framework to develop a prioritised roadmap for vaccine introduction during 2025-2030. DESIGN: Policy implementation case study applying a structured multicriteria decision analysis-informed prioritisation framework through a three-phase process including framework adaptation, evidence synthesis, ordinal ranking of candidate vaccines, weighted aggregation and development of sequencing scenarios. SETTING: National immunisation governance process in Iran, coordinated by the Ministry of Health and Medical Education and Iran's NITAG, with technical support from the WHO Country Office. PARTICIPANTS: Core and non-core members of Iran's NITAG and key immunisation stakeholders involved in the deliberative prioritisation process. RESULTS: Human papillomavirus (HPV) vaccine ranked highest in both importance and feasibility, followed by pneumococcal conjugate vaccine (PCV) for high-risk adults and seasonal influenza vaccine for high-risk groups. Two sequencing scenarios were proposed: both placed HPV first, with either PCV or influenza third after the already-approved hexavalent vaccine. Respiratory syncytial virus (RSV) and varicella vaccines were classified as low priority for the 5-year horizon. The toolkit enabled structured multistakeholder deliberation, improved the transparency and reproducibility of prioritisation, and supported systematic integration of epidemiological, economic and programme evidence. The main implementation challenges arose from national evidence constraints, particularly gaps in adult RSV and pneumococcal disease burden, limited locally generated cost-effectiveness analyses and uncertainty in long-term budget impact estimation under macroeconomic instability, rather than from limitations of the toolkit itself. CONCLUSION: The NVI-PST proved feasible under national leadership and generated credible, consensus-based recommendations aligned with Iran's public health priorities and programme constraints. Minor refinements (streamlined evidence compendium, simpler weighting, stronger secretariat support) would make the toolkit lighter and more sustainable, especially for resource-constrained settings. This Iranian experience provides a replicable model for structured multi-vaccine prioritisation in the Eastern Mediterranean Region and beyond.