Veterinary vaccine registration: Global regulatory standards, harmonization, and approval challenges

The global demand for veterinary vaccines is growing due to the rising incidence of transboundary animal diseases and the increasing recognition of animal health as a cornerstone of public and environmental well-being. Central to this effort is a robust and well-defined vaccine registration process, which ensures that products entering the market meet established standards of safety, quality, and efficacy. Despite progress, the veterinary regulatory landscape remains fragmented, with varying protocols, timelines, and expectations across countries and regions. This review critically examines global regulatory frameworks and key data requirements involved in veterinary vaccine development and approval, including the roles of key bodies such as the World Organisation for Animal Health (WOAH), the European Medicines Agency (EMA), and the USDA. Critical regulatory elements such as preclinical studies, efficacy trials, safety assessments, and manufacturing controls are discussed. The review further explores efforts toward harmonization through initiatives like VICH and One Health, emphasizing the importance of international collaboration and innovation. By synthesizing current knowledge and regulatory practices, it aims to inform policymakers, researchers, industry stakeholders, and regulatory bodies, fostering efforts toward harmonized, science-based, and adaptive regulatory frameworks. Future directions recommend investing in digital regulatory tools, developing emergency approval frameworks, and strengthening veterinary-specific infrastructure to ensure prompt access to safe and effective vaccines globally. The review underscores the urgent need for adaptive, science-based regulatory systems that can support rapid vaccine deployment in the face of emerging animal health threats.