Report of the international conference on animal testing replacement for vaccines: A one health view on global outlook and future strategy.

The transition toward non-animal methods for vaccine quality control has accelerated in recent years, driven by scientific advances and evolving regulatory expectations. To assess the current status of replacing animal-based methods, international stakeholders from regulatory authorities, industry, and public health institutions convened in Bangkok, Thailand from 2 to 4 December 2025 for the conference "Animal Testing Replacement for Vaccines: A One Health View - Global Outlook and Future Strategy," organized by Animal-Free Safety Assessment Collaboration and the International Alliance for Biological Standardization. This report synthesizes key discussions from the meeting, including advancements in in vitro potency, safety, and pyrogenicity testing; challenges associated with validation and global regulatory acceptance; access to critical reagents and reference standards; implementation of reliance and work-sharing models; and capacity building for national control laboratories across human and veterinary sectors. Despite recent progress in some areas, significant barriers remain, including fragmented regulatory requirements, limited access to reference standards, and inconsistent validation and implementation pathways across regions and sectors. Collectively, the outcomes underscore the need for coordinated international action to enable broader adoption of scientifically robust, non-animal testing strategies for quality control of vaccines.