Oral vaccination of the fox against rabies using a live recombinant vaccinia virus.

Rabies, a viral disease affecting all warm-blooded animals, is prevalent in most parts of the world, where it propagates amongst wild animals, particularly the fox and dog. The public health and economic consequences of infection in man and livestock are well known. Attempts to control the disease by vaccinating wild carnivores with inactivated or attenuated rabies virus remain controversial, and we have instead evaluated here the potential of a recombinant vaccinia virus to protect foxes against the disease. We have found that the administration of vaccinia virus (VV) or a recombinant harbouring the rabies surface antigen gene (VVTGgRAB) is innocuous to foxes. The recombinant virus can elicit the production of titers of rabies-neutralizing antibodies equal or superior to those obtained with conventional vaccine, and 10(8) plaque-forming units (PFU) of VVTGgRAB administered subcutaneously, intradermally or orally confers complete protection to severe challenge infection with street rabies virus.