Oral immunization of foxes by distributing vaccine baits was experimentally assessed and subsequently employed in the whole of the infected area of Belgium (10 000 km(2)). A vaccinia-rabies glycoprotein recombinant virus (VR-G) was used as vaccine because of its efficacy, safety and heat stability. Five 'full' campaigns offer vaccination, carried out from 1989 until 1991, induced a drastic decrease in the incidence of rabies. The disease has disappeared from the major part of the initial infected ar ea. In 1992 and 1993, three 'defence' campaigns, carried out along international borders, completely eliminated rabies virus infection from the fax population in 1993.