Evaluation of the Protection against Infectious Bursal Disease (IBD) Challenge in Progeny Born to Parents Having Received a Vaccination Program Using a Herpesvirus of Turkey-Infectious Bursal Disease (HVT-IBD) Vector Vaccine

Abstract

Broiler breeder vaccination against IBD is usually based on the injection of at least one inactivated vaccine in oil adjuvant, typically included in a combined vaccine. Priming using one or several IBD vaccine (s) has been the most common way to immunize the breeders so far. In summary, protection against vvIBD challenge in chicks of one commercial genetic line vaccinated in ovo with the HVT-IBD vector vaccine was demonstrated. The parents' IBD vaccination program, using the HVT-IBD vector vaccine alone, the HVT-IBD vector vaccine plus IBD inactivated vaccine, and inactivated IBD vaccine alone, did not impair their progeny's in ovo HVT-IBD vector vaccine take and subsequent protection against vvIBD virus challenge. An advantage in terms of immunization of the progeny against vvIBD was shown in the chicks born to breeders vaccinated with the HVT-IBD vaccine as a primer, as compared to breeders vaccinated with the inactivated vaccine alone. High level of IBD maternally-derived antibodies transmitted to the progeny by their parents induces together with an early onset of immunity by in ovo injection of a HVT-IBD vector vaccine clinical protection, as monitored on bursas, after vvIBD virus challenge.

Comparative Evaluation of HVT-IBD Vector, Immune Complex, and Live IBD Vaccines against vvIBDV in Commercial Broiler Chickens with High Maternally Derived Antibodies

“…Seroconversion was significant following vaccination with HVT-IBD vector vaccine at three weeks of age than non-vaccinated groups, but in comparison with other types of vaccines, it was not significantly different and the same occurred at four weeks of age, except with group D Although this vaccine is able to produce an immune response in presence of high MDAbs according to Kenezevic et al [45] and Berg [46], the results of IBDV antibody titers by classical ELISA kits confirmed what was reported by Chang et al [47] and Chang et al [48] that DNA vaccines induce low antibody ELISA titer that may be undetectable even after the IBDV challenge. Actually, the significant minimal seroconversion was recorded after the vvIBDV challenge on the HVT-IBD vector group (similar results were reported by Lemiere et al [49]), which may be explained by antibody titer that might be high enough to neutralize part of the challenged virus and prevent its replication, thus the classical ELISA kit used for detection of antibodies may not be a good estimator of the antibodies generated by the HVT-VP2 recombinant vaccine.…”

Cytokines, Serological, and Histopathological Assessment of Recombinant Vaccination Strategies for Combatting Infectious Bursal Disease in Broiler Chickens

“…The levels of IBDV antibodies were assessed through conventional ELISA kits, affirming previous results as outlined in the described method by [ 39 , 40 ], which indicated that DNA vaccines result in relatively low ELISA antibody titers. Remarkably, the limited seroconversion observed in the recombinant vaccine group after the vvIBDV challenge resembled the outcomes previously documented [ 41 ]. This might be attributed to the presence of high antibody titers that neutralized a portion of the challenged virus.…”

Efficacy of recombinant VAXXITEK HVT-IBDv vaccine against very virulent Infectious bursal disease virus (vvIBDv) challenge in layer chicks: A pilot study

“…It was also shown that the recombinant VAXXITEK HVT-IBDv vaccine provided a high maternal antibody titer in progeny from parents vaccinated with a single recombinant vaccine or if the rHVT-IBDv vaccine was combined with the inactivated vaccine, compared to a single inactivated vaccine. The protection of broiler chicks originating from parents vaccinated with the recombinant VAXXITEK HVT-IBDv which have been vaccinated with rHVT-IBDv in ovo was superior comparing to chicks originating from parents vaccinated with a single inactivated vaccine, even in the face of high levels of MDA (Lemiere et al, 2013). Authors concluded that the clinical protection of broilers under field conditions could be achieved after vaccination of parent flocks and their progeny with the rHVT-IBDv vaccines.…”