Subviral Particle Based Infectious Bursal Disease Vaccine for Chicken
Background:
Infectious bursal disease (IBD) also known as Gumboro disease of poultry caused by IBDV infects the bursa of Fabricius particularly the actively dividing and differentiating B lymphocytes in young chickens, resulting in morbidity, mortality and immunosuppression. Bursal damage and depletion of B cells enhances the susceptibility of chickens to other infections and interferes with vaccination against other diseases. Maternally derived antibodies (MDA) interfere with the vaccination of young chickens against IBD. In this context, live attenuated intermediate plus vaccines are better, however they cannot provide complete protection and induce moderate to severe clinical signs and immunosuppression. Hence, a better vaccine which overcomes this drawback is an absolute necessity in IBD outbreaks.
Technology Details
Subviral particle (SVP) based Infectious bursal disease vaccine is a recombinant vaccine intended for use against IBD also known as Gumboro disease of poultry. The IBDV major capsid protein VP2 on expression in yeast, Saccharomyces cerevisiae led to the formation of SVPs. The generated SVPs, in addition to their ability to stimulate antibody response, are highly effective in stimulating antigen specific lymphocyte proliferative and cytotoxic T lymphocyte responses. The SVP based vaccine completely protects the broiler birds in presence of maternally derived antibodies (MDA) and can safely be administered to day-old chicks. The vaccine does not cause immunosuppression as has been demonstrated by an intact histological architecture of the bursa of Fabricius in immunized birds. The efficacy of the SVPs against challenge with very virulent IBD virus was also evaluated at a poultry vaccine company M/S Globion India Pvt. Ltd., Hyderabad and the results indicated that the vaccinated flocks did not show any clinical signs indicating complete protection.