Field efficacy of different vaccines against infectious bursal disease in broiler flocks

Abstract

A field study was performed to determine the efficacy of three commercially available vaccines against infectious bursal disease (IBD) in commercial broilers raised in a high IBD virus (IBDV) risk area. Live attenuated intermediate and intermediate plus vaccines were used in four flocks. Birds were vaccinated orally at the estimated vaccination time. Three broiler flocks were vaccinated subcutaneously with a turkey herpesvirus (HVT)-IBD vector vaccine at one day old. Evaluation of the efficacy of different vaccines was focused on humoral immune response, bursa/body weight (B/Bw) ratio, molecular detection of IBDV in ileocaecal tonsils and bursa of Fabricius, and production parameters. The serological results showed that although the uptake of all three vaccine strains was confirmed in the lymphoid organs, no significant antibody response to vaccination was detected in flocks vaccinated with intermediate and intermediate plus vaccines. A significant increase in antibody titres detected in flocks vaccinated with the vector vaccine indicated its ability to induce an immune response in birds with a high level of maternally derived antibodies. Observations obtained in this field trial did not confirm the expected reduction of the B/Bw ratio in flocks vaccinated with less attenuated vaccines. No significant differences were observed between birds vaccinated with the vector vaccine and those immunised with the intermediate plus vaccine. Very virulent IBDV was confirmed in the flock vaccinated with the intermediate vaccine. The infection induced reduced B/Bw and moderate mortality but did not affect the production parameters. Field infection was not detected in broilers vaccinated with the intermediate plus vaccine and the vector vaccine.

Comparison of infectious bursal disease live vaccines and a HVT-IBD vector vaccine and their effects on the immune system of commercial layer pullets

“…Hence in HVT-IBD, HVT is used as a vector expressing the protective IBDV-VP2 to achieve protection against IBDV. This HVT vector vaccine can be administered by the in ovo route between 3 and 2 days before hatching or by the subcutaneous route in one-day-old chicks (Bublot et al, 2007;Lemiere et al, 2011;Zorman Rojs et al, 2011). Due to the mechanism of action of vHVT-IBD, the immune response and the subsequent protection against IBDV are triggered only by the IBDV-VP2 protein expressed by the vector during replication.…”

Isolation, Characterization and Standardization of New Infectious Bursal Disease Virus for Development of a Live Vaccine

“…IBDV primarily impairs the humoral immune response which is followed by sever immunosupression due to down regulation of T cells and macrophages which leads to an increased susceptibility to other pathogens (2,4,8). IBD vaccination program including priming with a live attenuated followed by boosting with an inactivated vaccine is used for vaccinating parent stocks (13,17). A careful selection of virus strains with a sensitive method of determining virulence is important when establishing a live virus vaccine (10).…”

“…A live attenuated vaccine based on a classical virulent strain was developed to provide maternal immunity to the off-springs. The use of live IBDV vaccine has been very successful in controlling the disease, with the aim of maintaining the immune response induced by the parent virus (11)(12)(13)(14). The live vaccine mimics infection in poultry and can induce both cellular and humoral immunity.…”

Characterization of two recombinant HVT-IBD vaccines by VP2 insert detection and cell-mediated immunity after vaccination of specific pathogen-free chickens

“…The HVT vaccine has been widely used in chickens since the 1970s for inducing long-term cross-protection against Marek's disease, which is caused by Marek's disease virus (Okazaki et al, 1970;Purchase et al, 1972). The HVT vaccine is less sensitive to maternal-derived antibodies than traditional attenuated IBDV vaccines (Darteil et al, 1995;Tsukamoto et al, 2002;Bublot et al, 2007;Le Gros et al, 2009;Perozo et al, 2009;Zorman Rojs et al, 2011). Moreover, the HVT vaccine can be securely injected in ovo or in day-old chicks and presents no immunosuppressive effects (Reddy et al, 1996;Prandini et al, 2016).…”