Safety and efficacy of an antirabies vaccine consisting of recombinant vaccinia-rabies virus administered orally to the fox, dog and cat

peer reviewedOne of the most promising ways to control rabies in wildlife seems to be the distribution of bait containing an anti-rabies vaccine. So far, the most widely used vaccines were modified live viruses (SAD strain or derivatives). Nevertheless, these strains retain some pathogenicity for non-target species. A novel vaccine was proposed consisting of genetically modified vaccinia virus (strain Copenhagen, thermosensitive ts 26) expressing the foreign glycoprotein G for the rabies virus (strain ERA). Different doses of this recombinant virus were administered orally to 59 foxes (Vulpes vulpes) and their antibodies were titrated before challenge. Foxes (8/8) resisted 1 month after vaccination with 10(7) plaque forming units (PFU), or 4/4 after 18 months. Seroconversion among dogs was 4/4 after vaccination with 10(9,6) PFU and 4/4 among cats after vaccination with 10(8) PFU. These dogs (4/4) and cats (3/4) resisted the challenge 2-3 months after vaccination. This vaccine thus appears to be potent and safe in these species. Its properties are discussed