IgY passive immunotherapy for pandemic preparedness: a One Health platform approach against pathogen X.

SUMMARYThe rising threat of emerging infectious diseases, especially zoonotic pathogens crossing species barriers, highlights the urgent global need for scalable, rapid-response passive immunotherapy platforms. Chicken egg yolk-derived immunoglobulin Y (IgY) antibodies offer unique conceptual and practical advantages. This review critically evaluates IgY antibodies (IgY-Abs) as a One Health immunotherapeutic strategy with strong potential for mitigating zoonotic spillover risks. Drawing on insights from SARS-CoV-2, we highlight the advantages of IgY-Abs over traditional approaches in specific scenarios while emphasizing their role as a complementary rather than replacement platform within the broader passive immunotherapy landscape. We discuss key strategic considerations, regulatory challenges, and essential knowledge gaps. Finally, we propose a forward-looking research and development roadmap that emphasizes interdisciplinary collaboration, optimized production methods, targeted regulatory frameworks, and integrated One Health strategies to facilitate the rapid deployment of IgY-based countermeasures against WHO-priority zoonotic pathogens.