This report summarizes the proceedings from an international meeting organized by PATH and partners and held in Bangkok, Thailand, from September 3 to 4, 2025 for manufacturers and regulatory testing laboratories on polio vaccine quality control assays.

Presenters provided updates on evolving guidance for the implementation of quality control assays for polio vaccines. This included the dissemination of results from a recent World Health Organization (WHO) collaborative study supporting the replacement of animal models with high-throughput sequencing for routine vaccine lot release.

Other topics included the latest WHO collaborative study results on the suitability of the Sabin inactivated polio vaccine International Standard for in vivo rat potency testing; the availability of WHO universal reagents for polio vaccine potency assays; and the importance of harmonizing in-house assay standards and reagents with international standards and the WHO guidance.

Finally, presenters discussed the potential of next-generation products, such as S19 virus-based IPV, that can be developed currently without biocontainment requirements.