Evaluation of Anatomopathological, Serological, Immunological Responses and Protection in Broilers Vaccinated With Live Infectious Bursal Disease Vaccines

Abstract

The study was divided into three experiments. In the first one, broilers were distributed into six groups and vaccinated against infectious bursal disease at 14 days of age: T1-not vaccinated, T2-Lukert1 (intermediate), T3-Lukert2 (intermediate plus), T4-228E, T5-V877 and T6-Winterfield 2512 (“hot” strains). Bursas of Fabricius (BF) were collected at 17, 21, 28 and 35 days to measure BF relative weight (BFRW), diameter, histological examination and image processing analysis (IPA). At one, 14, 21, 28 and 35 days of age, samples of blood taken from eight birds from each group for serology analysis by ELISA test. Hot strains vaccines induced reduction of BFRW and BF diameter, higher histological score lesion degree, more lymphocyte depletion on the BF follicles and higher IBD antibody titer. In the second experiment, 16 birds from groups T1 to T6 were isolated and challenged with a very virulent strain of IBDV (vvIBDV) at 25 days of age. Only groups T4, T5 and T6 were totally protected against vvIBDV challenge. In the third experiment, the immunosuppressive potential of each vaccine was determined by examining the ability of IBDVvaccinated birds to respond to Newcastle disease (ND) vaccination and challenge. None of the vaccines was found to be immunodepressive.

Evaluation of Serum Conversion Induced by Infectious Bursal Disease Vaccines Submitted to Official Quality Control in the Period 2013 to April 2014

“…To be able to evaluate vaccine efficacy in commercial broilers, parameters such as intrabursal IBDV-antigen load should also be considered in conjunction with bursa lesion scores. The result of antibody titer obtained in monovalent vaccines Winterfield strain for us is concordant of the find by Nishizawa M, et al [9] the vaccine strain induced high IBD antibody titer. De Witt JJ, et al [10] showing the results of global proficiency testing schemes (PTS) for serological tests to detect antibodies against IBDV in chicken serum, in which 125 laboratories participated from Africa, Asia, Europe, Central and South America using: virus neutralization (VN) enzyme-linked immunosorbent assays (ELISA) and agar gel precipitation (AGP).…”

“…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. Considering the results obtained with the monovalent and immunecomplex IBD vaccines, all tested batches resented minimum values required by Brazilian legislation (9), therefore being approved.…”

Comparison of the Immunogenicity and Pathogenicity of a Genetically Engineered Infectious Bursal Disease Virus Vaccine and Two Commercial Live Vaccines in Chickens with Maternal Antibodies

“…B/Bw ratio is one of the most important parameters to evaluate residual pathogenicity of IBDV vaccines [18]. In general, a hot IBDV vaccine, such as an intermediate plus vaccine, 228E, is capable to destroy B-lymphocytes present on the BF, reduces their size and therefore causes considerable reduction in B/Bw ratio than a mild IBDV live vaccine [19]. However, in the present study, no significant changes in the B/Bw ratios and minimal…”