Latest Findings in Immunoglobulin Y Technologies and Applications.

Immunoglobulin Y (IgY), the major antibody class in birds, has gained increasing attention in recent years as a versatile and ethically sustainable alternative to mammalian immunoglobulins. IgY has demonstrated strong potential in diagnostics, prophylaxis, and therapy across a wide range of fields, including infectious diseases, allergy management, oral health, and food safety. Its applications in animal health-particularly in poultry, livestock, and companion animals-further underscore its relevance within the One Health framework. This review provides a comprehensive synthesis of IgY technology, starting with its physiological role in maternal immunity and the structural characteristics that distinguish it from mammalian immunoglobulin G (IgG). This review outlines current strategies for IgY production and purification. It also provides an overview of its biomedical and veterinary applications, including its use in diagnostics, prevention, and treatment-such as for SARS-CoV-2-primarily based on studies published in the past five years. The final section addresses the current limitations of IgY technology, such as variability in protocols, stability challenges, and the need for safety assessment, while highlighting the importance of harmonized guidelines to support broader implementation. With growing scientific interest, expanding clinical research, and increasing availability of commercial products, IgY is well positioned to become a valuable immunobiological tool for both human and veterinary applications.