Recombinant rabies vaccines: efficacy assessment in free-ranging animals

RUPPRECHT, C.E., HANLON, C.A., NIEZGODA, M., BUCHANAN, J.R., DIEHL, D. & KOPROWSKI, H. 1993. Recombinant rabies vaccines: efficacy assessment in free-ranging animals. Onderstepoort Journal of Veterinary Research, 60:463--468 With the advancement of recombinant DNA techniques, a number of potent biologicals are available for the oral vaccination of free-ranging animals. Once oral immunogenicity and vaccine safety have been de­ monstrated, efficacy then becomes of paramount importance. Classical assessment of efficacy is con­ ducted under carefully controlled laboratory conditions, whereas efficacy of oral wildlife rabies vaccination programs, to date, have been assessed by the lack (or occurrence) of field cases of rabies in a vaccinated area. This communication describes an intermediate vaccine efficacy strategy in which self-vaccinated, free-ranging animals from a study site were captured seven months after vaccine-laden bait distribution for laboratory rabies challenge. This technique is specifically reviewed in the context of available recom­ binant products for the consideration of extension towards dog rabies control.