Infectious Bursal Disease: Pathogenicity and Immunogenicity of Vaccines

Abstract

The Infectious Bursal Disease (IBD) is a contagious viral disease that affects young chickens and may cause high morbidity and mortality. As the virus is very resistant to the environment, vaccination is required in case of high infection pressure. Due to variations in the virulence degree of the vaccines available to control IBD, this study aimed at evaluating the pathogenicity and immunogenicity of three types of vaccines. In total, 220 one-day-old specific pathogen free (SPF) chickens were immunized with recombinant, immune-complex and intermediate vaccines, or not vaccinated (55 birds per group) and challenged with IBD G11 strain on day 25. On days 25, 30, and 35, the Bursa of Fabricius (BF) were submitted to gross and histological examination, and serum samples were submitted to ELISA to determined anti-IBD antibody titers. On day 23, chickens were submitted to the test of hypersensitivity to phytohemagglutinin to evaluate the immunosuppressive effect of vaccines on the cell-mediated immunity. The results have indicated that the immune-complex vaccine induced the most severe BF lesions, whereas the recombinant vaccine preserved BF tissue and cell integrity. The three evaluated vaccines induced humoral immunity of similar intensity. The cellular reaction to phytohemagglutinin of the chickens immunized with recombinant and immune-complex vaccines was less severe compared with the unvaccinated chickens. In conclusion, these results indicate that the immune-complex vaccine was the most pathogenic and that all vaccines were effective in protecting SPF chickens against IBD.

Prevalence of infectious diseases in Sonali chickens at Bogra Sadar Upazila, Bogra, Bangladesh

“…Among the 258 Sonali chickens examined in this study, IBD was recorded in 14.72% (n=38/258) chickens, whereas ND, Coccidiosis, Colibacillosis and Mycoplasmosis were found in 11.24% (n=29/258), 13.95% (n=36/258), 14.72% (n=38/258), and 12.79% (n=33/258) samples respectively ( (Camilotti et al 2016). In our study, mixed infection of the diseases were very common in the study area.…”

Histopathology and Serology Reaction to an Immune Complex Infectious Bursal Disease Vaccine (V877 Strain) in SPF and Commercial Birds

“…An important feature within the strains of attenuated IBDV chosen to constitute a vaccine is its capacity of immunogenicity without producing severe lesions in the bursal parenchyma (CAMILOTTI et al, 2011). This avoids the undesirable effect of vaccination inducing some immunosuppression (MORAES et al 2004).…”

Molecular epidemiologic survey of infectious bursal disease viruses in broiler farms raised under different vaccination programs

“…While on the one hand, the live vaccine is susceptible to neutralization by high maternal antibodies [1], there is also the potential for immunosuppression if flocks are vaccinated when they are young or if their antibody levels are too low [2][3]. Different vaccine strains vary with regard to these issues [4], which is why producers have more frequently turned to immune complex and recombinant vaccines that can be administered safely and effectively from the hatchery. Today, these 2 types of IBD vaccines are used to control IBD on most Brazilian farms.…”