Pathological and Immunological Study of an in ovo Complex Vaccine against Infectious Bursal Disease

Abstract

The appearance of very virulent strains of infectious bursal disease (IBD) virus at the end of the 1980s made it necessary to develop more effective immunization procedures. To facilitate this, the immunogenicity and the immunosuppressive effect of a mild (G-87), an intermediate (LIBD) and an intermediate-plus (IBDV 2512) IBDV strain were tested after the in ovo inoculation of 18-day-old SPF and broiler chicken embryos. It was established that no noteworthy difference existed between the immunized and the control embryos in hatching rate and hatching weight. The higher the virulence of the vaccine virus strain, the more severe damage it caused to the lymphocytes of the bursa of Fabricius. In SPF chickens, the haemagglutination inhibition (HI) titres induced by a Newcastle disease (ND) vaccine administered at day old decreased in inverse ratio to the virulence of the IBD vaccine strain, while in broiler chickens this was not observed. Despite the decrease of the HI titre, the level of protection did not decline, or did so only after the use of the 'hot' strain. SPF chickens immunized in ovo with a complex vaccine prepared from strain IBDV 2512 and IBD antibody showed the same protection against Newcastle disease as the broilers. In broiler chicken embryos immunized in ovo, only strain IBDV 2512 induced antibody production, and such chickens were protected against IBD at 3 weeks of age. The complex vaccine administered in ovo has been used successfully at farm hatcheries as well.

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

“…In ovo administration (at embryonation day 18) of IBDV, immune complex vaccine was shown to generate antibodies against IBDV causing protective immunity in both specific pathogen free and broiler embryos (43,46). The same vaccine when administered subcutaneously to one day old chicks resulted in a detectable antibody response (24,43).…”

Evaluación De Dos Vacunas Comerciales Conteniendo El Complejo Antígeno Anticuerpo Contra La Infección Bursal en Pollos De Carne

“…El comportamiento productivo del grupo A fue ligeramente superior, aunque no significativo a los grupos C y D. Resultados similares han sido reportados por Kelemen et al (2000) donde durante el periodo de desafío, los pollos vacunados con el complejo Ag/ Ac tuvieron mayor peso corporal que las aves vacunadas con una vacuna convencional no ligada a anticuerpos. Las diferencias en la ganancia de peso entre los grupos A y B que recibieron el complejo Ag/Ac, ambas con el virus vacunal 2512, se puede deber a que las vacunas no son producidas por la misma compañía, y las vacunas pueden contener diferentes cantidades de anticuerpos específicos, composición que es confidencial de las empresas.…”

“…Adicionalmente, todas las aves fueron vacunadas contra la Enfermedad de Newcastle y Bronquitis Infecciosa en la planta de incubación y a los 16 Los cuatro grupos experimentales fueron criados en ambientes separados hasta los 35 días de edad. Luego, 45 aves de cada grupo fueron trasladadas al galpón de experimentación para ser desafiadas, vía ocular, con la cepa F52/70 de la EIB a una dosis de 50 uL/ave.…”

Automated mass immunization of poultry: the prospect for nonreplicating human adenovirus-vectoredin ovovaccines

“…It is common for broiler chickens to be vaccinated for several diseases prior to leaving the hatchery. Simultaneous in ovo administration of MLVs routinely occurs without interference among themselves [2,3,13] or with day-of-hatch vaccines for ND and IB [14,15].…”