Oral immunization of raccoons and skunks with a canine adenovirus recombinant rabies vaccine

Oral vaccination is an important part of wildlife rabies control programs. Currently, the vaccinia-rabies glycoprotein recombinant virus is the only oral rabies vaccine licensed in the United States, and it is not effective in skunks. In the current study, captive raccoons and skunks were used to evaluate a vaccine developed by incorporating the rabies virus glycoprotein gene into a canine adenovirus serotype 2 vector (CAV2-RVG). Seven of 7 raccoons orally vaccinated with CAV2-RVG developed virus neutralizing antibodies and survived lethal challenge. Five of 5 and 6 of 6 skunks in 2 experimental groups receiving 10-fold different dilutions of CAV2-RVG developed neutralizing antibodies and survived challenge. The results of this preliminary study suggest that CAV2-RVG stimulates protective immunity against rabies in raccoons and skunks.