Vaccination of white-tailed deer (Odocoileus virginianus) with Mycobacterium bovis bacillus Calmette Guerı́n

Wildlife reservoirs ofMycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock. In Michigan, SA tuberculous white-tailed deer transmit M. bovis to cattle. One approach in dealing with this wildlife reservoir is to vaccinate deer in order o interrupt the cycle of deer to deer and deer to cattle transmission. Thirty-one white-tailed deer were assigned to one of three groups; 2 SC oses of 107 CFU of M. bovis BCG (n= 11); 1 SC dose of 107 CFU of M. bovis BCG (n= 10); or unvaccinated deer (n= 10). After vaccination, eer were inoculated intratonsilarly with 300 CFU of virulent M. bovis. Gross lesion severity scores of the medial retropharyngeal lymph ode were significantly reduced in deer receiving 2 doses of BCG compared to unvaccinated deer. Vaccinated deer had fewer lymph node ranulomas than unvaccinated deer, and most notably, fewer late stage granulomas characterized by coalescent caseonecrotic granulomas ontaining numerous acid-fast bacilli. BCG was isolated from 7/21 vaccinated deer as long as 249 days after vaccination. In one case BCG as transmitted from a vaccinated deer to an unvaccinated deer. In white-tailed deer BCG provides measurable protection against challenge ith virulent M. bovis. However, persistence of vaccine within tissues as well as shedding of BCG from vaccinates remain areas for further nvestigation. ublished by Elsevier Ltd.