DO WE NEED ORAL BAIT VACCINATION TO ELIMINATE DOG MEDIATED HUMAN RABIES?

Abstract

Oral rabies vaccines (ORVs) have been used successfully to control rabies in carnivore reservoir populations across the globe. Fox rabies was eliminated from Europe through strategic distribution of ORVs across Western Europe from 1978. The vaccine strains have been modified repeatedly to improve safety and immunogenicity through modern technologies such as monoclonal selection, recombination, and reverse genetics. The 3rd generation ORVs developed for canids used reverse genetics to enable site-especific modifications at G protein encoding regions. These vaccines have been demonstrated to be safe and robust for the use in free roaming dogs in close proximity to human populations. Over 99% of human rabies deaths in endemic regions are the result of transmission from dogs. Although effective delivery of post exposure prophylaxis can prevent 100% of dog mediated human rabies, the source of transmission will continue to be a threat, indefinitely burdening the health sector. Mass dog vaccination is a proven approach to eliminate dog mediated human rabies, however accessing a sufficiently high proportion of the dog population by parenteral approaches remains a significant technical barrier to district-level campaigns across much of South Asia. The introduction of ORVs as an additional tool to parenteral vaccination methods can increase vaccination coverage in roaming dog populations, may reduce the operational cost and management of mass dog vaccination, therefore improving the feasibility of control efforts. ORVs are proven to be an effective tool in controlling canine rabies through feasibility studies, simulations and field trails demonstrating the ease of distribution and improved coverage. Structuring mass dog vaccination techniques to be more feasible would also encourage local authorities to attempt control canine and dog mediated human rabies.