A recombinant canarypox virus protects rabbits against a lethal rabbit hemorrhagic disease virus (RHDV) challenge

An ALVAC (canarypox)-based recombinant virus ALVAC-RHDV (vCP309) expressing a native rabbit hemorrhagic disease virus (RHDV) capsid protein was derived and assessed for its protective efficacy in rabbits. Protection against a lethal RHDV challenge was demonstrated in rabbits inoculated twice with either high (10(7) p.f.u.) or low (10(5) p.f.u.) doses of vCP309. However, animals in the high dose group developed significantly higher antibody response. These results have implications that are relevant to the development of a safe rabbit hemorrhagic disease (RHD) vaccine and further illustrate the utility of the ALVAC vector system to elicit protective immune responses in nonavian species.