Canine adenovirus antibodies in meso-carnivores in the United States of America: implications for oral rabies vaccination using recombinant adenovirus vaccines?

摘要

A recombinant canine adenovirus (serotype 2) rabies glycoprotein vaccine (CAV2-RG) has demonstrated efficacy in protecting against rabies in captive striped skunks and raccoons. In addition, the vector for this vaccine is unlikely to pose potential public health concerns such as those associated with other recombinant oral rabies vaccines currently in use in North America. In preparing to evaluate CAV2-RG as a prospective candidate for field testing, we conducted serological surveys representing a diverse range of meso-carnivore rabies reservoir species in North America to determine baseline CAV virus-neutralising antibodies (VNA). Of the 1,128 animals included in this analysis, 22.7% (n =256) tested positive for CAV VNA. This CAV VNA presence differed among species (P < 0.05), and was the lowest among raccoons (Procyon lotorj (3.4%, n = 610) and highest among coyotes fCanis latransj (78.4%, n =116). Similar (P > 0.05) intermediate CAV VNA activity was observed in the small Asian mongoose (Uerpestes javanicus,) (27.1%, n = 85), striped skunk (Mephitis mephitis,) (37.3%, n = 201), and gray fox (Urocyon cinereoargenteusj (39.7%, n = 116). No CAV VNA was detected in mongoose samples from Hawaii (n=31, 2011), but a 42.6% (n = 54) presence was observedin Puerto Rico. These findings suggest that meso-carnivores more distant phylogenetically from Can is species would probably respond more favourably to field application of CAV2-RG presented in a proper bait formulation. However, due to background CAV VNA levels, CAV2-RG may not be expected to be equally effective in oral rabies vaccination campaigns in all meso-carnivore rabies reservoir species in North America, irrespective of bait formulation. This limitation, together with the current economic climate and other limiting factors, underscores the need for access to a single, safe, inexpensive oral rabies vaccine in the United States that is efficacious in all meso-carnivore rabies reservoir species.