Chitosan-coated PLGA nanoparticles as a delivery system for infectious bursal disease viral antigen in chickens.

In the present study, antigen-chitosan-PLGA nanoparticles were explored as the delivery system for inactivated whole infectious bursal disease virus (IBDV) antigens. The immunized birds showed the peak antibody level (ELISA titre 4095.65 ± 55.74) at the 3rd week post-immunization, which was significantly higher than that of the commercial inactivated vaccine (titre 2257 ± 30) (P < 0.0001). The virus-loaded chitosan-coated PLGA nanoparticles induced good cell-mediated immunity. The immunized birds showed better resistance against the challenge infection with a very virulent IBDV. Only one bird out of the five challenged showed viral antigens in the bursa (80% protection), whereas, in the commercial vaccinated group, two chickens showed viral antigens in the bursa (60% protection). The histopathological lesions were also found to be very mild in the same group. The birds which were immunized with the antigen-chitosan-PLGA nanoparticles did not show any sign of immunosuppression. It is concluded that antigen-chitosan-PLGA nanoparticles afford the best protection among the groups, which lays a foundation for further development of a vaccine delivery platform in this line.RESEARCH HIGHLIGHTS First report on the use of Chitosan/PLGA nanoparticles with inactivated IBD virus.Nanoparticles prepared by solvent evaporation method.Elicited better humoral and cell-mediated immunity in chickens.Protection is better than commercial vaccine.