IgY: A Key Isotype and Promising Antibody for the Immunoprophylaxis Therapy of Infectious Bursal Disease Virus Infections

The infectious bursal disease (IBD) is a highly contagious and acute poultry disease caused by Birnavirus. However, the vaccination is the only disease prevention, but several factors impeded vaccine development. Thus, a need for time to develop a novel technique for managing and treating respiratory diseases in poultry birds. Passive immunization is a hope and a possible alternative used in birds to meet this need. The current research attempted to produce egg yolk-based polyclonal antibodies against the IBD virus. The benefits of IgY include ease of extraction, lack of reaction with mammalian Fc receptors, and low production cost. Commercial layers were immunized with inactivated IBD virus subcutaneously according to the treatment regimen. The eggs were gathered daily, and yolk antibodies were extracted with the ammonium sulfate precipitation technique. The use of an indirect hemagglutination test demonstrated that IgY was IBD-specific. Until the end of the experiment, the specific IgY immunoglobulins did not lose activity when stored at 4℃. The specific immunoglobulin (IgY) treated challenged birds were demonstrated 92% recovery in comparison to the control group. The study implies that the IBDV specific IgY is an easily prepared and rich source of antibodies and offers an alternative therapeutic agent to cure IBD-infected birds.