Efficacy of a Novel Infectious Bursal Disease Virus Immune Complex Vaccine in Broiler Chickens

Abstract

Two experiments were conducted to test the efficacy of a novel infectious bursal disease virus (IBDV) vaccine in broiler chickens with maternal IBDV immunity. The IBDV vaccine was formulated by mixing IBDV strain 2512 with bursal disease antibodies (BDA) to produce the IBDV-BDA complex vaccine. In Expt. I, 1-day-old Cobb x Cobb broiler chickens were vaccinated subcutaneously with either IBDV-BDA or commercial live intermediate IBDV vaccine (vaccine A) or were left unvaccinated. In Expt. 2, the vaccine A group was not included; instead, IBDV strain 2512 was included. Chickens were maintained in isolation houses. On day 28 (Expt. 1) and day 32 (Expt. 2) of age, chickens from each group were challenged with a standard USDA IBDV (STC strain) challenge. Challenged and unchallenged chickens were evaluated for their bursa/body weight ratios and antibody titers 3 days post-challenge. Bursae collected from Expt. 2 were examined histologically to evaluate bursal lesions and confirm gross examination. None of the unvaccinated chickens was protected against the challenge virus as evidenced by the presence of acute bursal lesions (edema/hemorrhage). All chickens receiving the IBDV-BDA complex or the IBDV strain 2512 (Expt. 2) were protected from the challenge virus as evidenced by no acute bursal lesions. Additionally, chickens receiving the IBDV-BDA complex vaccine or the IBDV strain 2512 had antibody titers to IBDV, indication the presence of an active immune response. In Expt. 1, chickens vaccinated with vaccine A and challenged had bursal lesions similar to those observed in the unvaccinated, challenged chickens. These chickens also showed no indication of active immunity against the virus. These results suggest that the 1-day-of-age-administered IBDV-BDA complex vaccine can induce active immunity and protection against a standard IBDV challenge in the face of variable levels of maternal IBDV immunity.

Comparison ofin ovoand post‐hatch vaccination with particular reference to infectious bursal disease. A review

“…The same vaccine when administered subcutaneously to one day old chicks resulted in a detectable antibody response (24,43). In most studies, it has been clearly indicated that chickens vaccinated as embryos acquire higher antibody levels that are sustained at high levels over the normal broiler's rearing period.…”

Infectious Bursal Disease: Pathogenicity and Immunogenicity of Vaccines

“…The immune-complex vaccine, on the other hand, is innovative compared with conventional live vaccines because the vaccine virus is coated with anti-IBD antibodies, and when administered to one-day-old chicks, its pathological effects are delayed up to one week, during which the level of maternal antibodies is greatly reduced (Haddad et al, 1997;Jeurissen et al, 1998).…”

“…Despite the BF lesions caused by immune-complex vaccines, some researchers stated that the vaccine antibodies may reduce the pathogenicity of the virus, resulting in less severe depletion of B lymphocytes when compared with live vaccines with the same virus strain (Haddad et al, 1997;Jeurissen et al, 1998). On the other hand, Moraes et al (2004) recommends caution when using live vaccines that may cause BF lesions, as the recovery of bursal follicles may be only partial.…”

“…In their study, commercial birds exhibited bursal depletion later (starting on day 33), was less severe, and for a shorter time than SPF birds, in which depletion started 7 days post-vaccination. In addition, several studies have shown that the immune-complex vaccine is an excellent alternative for the vaccination of broiler chickens, promoting high levels of maternal antibodies, providing total protection against heterologous strains, and do not affect live performance (Haddad et al, 1997;Avakian et al, 2001;Chansiripornchai & Sasipreeyajan, 2009;Santos, 2009).…”

Transgenic Plant Vaccine: A Breakthrough in Immunopharmacotherapeutics

“…This immune complex vaccine is developed by mixing live intermediate plus infectious bursal disease virus (IBDV) with hyperimmune IBDV chicken serum (IBDV-Icx vaccine) [38].…”