Oral rabies vaccination: an overview.

The vaccination of wild animals against rabies was first attempted in 1962 after the repeated failure of poisoning or trapping to control the movement of the disease in these species. The initial requirements of such a vaccine were that it be efficacious and inexpensive, that it allow animals to immunize themselves, and that it not cause vaccine rabies in the target species. Foxes were chosen for research purposes because they are a problem species and are exquisitely susceptible to rabies. The first successful laboratory studies with attenuated vaccine came in 1971, and the first field trial (successful) was carried out in Switzerland beginning in 1978. Other species have not yet been immunized in the field.