In Vivo Safety Studies With SPBN GASGAS in the Frame of Oral Vaccination of Foxes and Raccoon Dogs Against Rabies.

In order to obtain Marketing Authorization for an oral rabies vaccine in the European Union, not only safety studies in the target species, red fox and raccoon dog, are required. Since baits are distributed unsupervised in the environment, specific safety studies in selected non-target species are compulsory. Furthermore, oral rabies vaccines are based on live, replication-competent viruses and thus distinct safety studies in the target species for such type of vaccines are also mandatory.

Safety studies with the oral rabies virus vaccine strain SPBN GASGAS in the small Indian mongoose (Herpestes auropunctatus).

Background: Oral vaccination of the small Indian mongoose against rabies has been suggested as a potential tool to eliminate mongoose-mediated rabies on several Caribbean islands. A recently developed oral rabies virus vaccine strain, SPBN GASGAS, has already been shown to be efficacious in this reservoir species. Since, all available oral rabies vaccines are based on replication-competent viruses and vaccine baits are distributed unsupervised in the environment, enhanced safety standards for such vaccine types are required.

Efficacy of the oral rabies virus vaccine strain SPBN GASGAS in foxes and raccoon dogs.

To test the immunogenicity and efficacy of a new oral rabies virus vaccine strain SPBN GASGAS in wildlife target species, one group of foxes and two groups of raccoon dogs were offered a bait containing 1.7 ml of the vaccine (10 FFU/ml; 10 FFU/dose) and subsequently challenged approximately 180 days later with a fox rabies virus isolate. One group of raccoon dogs (n=30) received the same challenge dose (10 MICLD/ml) as the red foxes (n=29).

Oral vaccination of wildlife against rabies: Differences among host species in vaccine uptake efficiency.

Oral vaccination using attenuated and recombinant rabies vaccines has been proven a powerful tool to combat rabies in wildlife. However, clear differences have been observed in vaccine titers needed to induce a protective immune response against rabies after oral vaccination in different reservoir species. The mechanisms contributing to the observed resistance against oral rabies vaccination in some species are not completely understood.