Oral immunization against rabies: afterthoughts and foresight

Abstract

The article contains personal views on some issues that are frequently addressed in discussions about rabies control, and on some related topics that are often overlooked. The first field applications of oral wildlife rabies immunization in the Swiss Rhone Valley were preceded by many years of international cooperative studies on efficacy and safety. They were significant "faits accomplis" that facilitated similar endeavors in other countries. Some aspects of the residual pathogenicity of oral rabies vaccines are discussed. The field efficacy of oral wildlife immunization is the outcome of complex interactions between vaccine and bait attributes, bait distribution procedures, and habitat properties. Significant difficulties hinder the interpretation of field observations on efficacy. Though oral wildlife immunization is not an animal welfare act and not a conservationist achievement, it is an attempt at zoonosis control intended to protect human health and prevent economic losses.