[New research on the oral vaccination of wild animals]

Abstract

Successful oral immunization of wildlife against rabies has strongly stimulated research in the past decade. New approaches have been developed for vaccine production (e.g.: use of recombinant vaccines) as well as for better potency or safety testing procedures. It appears that Man should also consider two important phenomena which already existed in nature before his research. The first one is an adaptation of the rabies virus, by serial passages, which favours the spreading of the disease among a sole animal species. Bites of this species vaccinate other species more often than they kill them, leading sometimes, to the mutual exclusion of potential vector. The next phenomenon is the self-control of the first one due to an over-adaptation of the virus to its vector species. It leads to unappropriate level, or delay, of reexcretion of the virus, therefore to the transformation of a rabies epizootics into rabies enzootics. Oral vaccination would thus appear as an useful tool to eradicate the disease after it reached this enzootic stage.