A recombinant subunit vaccine that protects progeny chickens from infectious bursal disease

Abstract

The major protective immunogen of infectious bursal disease virus (IBDV), VP2, was produced in a highly immunogenic form by expression in the yeast Saccharomyces cerevisiae. The recombinant protein, formulated as an oil-emulsion vaccine, induced both virus neutralising and ELISA antibodies in specific pathogen free hens. These antibodies were passed, via the egg yolk, to progeny chickens and protected them against a challenge infection with virulent IBDV. The protective efficacy of maternal antibodies to the recombinant VP2, as assessed by ELISA, was comparable to that of antibodies to the whole virus. The recombinant subunit vaccine induced anamnestic serum antibody responses in hens primed previously with live virus, and hence can replace the conventional inactivated vaccines administered to breeding hens.