Virus-like-particle (VLP) vaccines for infectious bursal disease virus (IBDV).

Developing nations rely on poultry as their major protein source. Maintaining poultry health is of critical importance to good human nutrition worldwide. Infectious bursal disease is a contagious immunosuppressive disease affecting nearly all poultry producing regions of the world. The disease is caused by infectious bursal disease virus (IBDV) a bi-segmented double-stranded RNA virus. Vaccination of breeder flocks to produce maternal immunity in the chicks is used to control IBD. Control efforts are complicated by frequent genetic mutations, reassorting of genome segments and genetic recombination that can increase virulence and alter antigenicity which renders vaccines ineffective. The current practice of producing inactivated IBDV vaccines using virus grown in chicks is expensive and time consuming. We have demonstrated that in vitro production of multivalent virus-like-particles (VLPs) has the potential to solve these problems. The objectives of this project are to determine the optimal dosage of IBDV-VLP vaccines containing VP2 proteins from multiple antigenic strains of the virus and to complete safety and efficacy studies required for licensure by the USDA Center for Veterinary Biologics.