Vaccination of White-tailed Deer (Odocoileus virginianus) with Mycobacterium bovis bacillus Calmette Guerin

Authors: Palmer, Mitchell; Thacker, Tyler; Waters, Wade

Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2007
Publication Date: 9/4/2007
Citation: Palmer, M.V., Thacker, T.C., Waters, W.R. 2007. Vaccination of White-tailed Deer (Odocoileus virginianus) with Mycobacterium bovis bacillus Calmette Guerin. Vaccine. 25(36):5489-97.

Interpretive Summary: Wildlife reservoirs of tuberculosis represent serious obstacles to the elimination of tuberculosis in domestic animals. In Michigan, USA diseased white-tailed deer transmit tuberculosis to cattle. One approach in dealing with this wildlife reservoir is to vaccinate deer in order to interrupt the cycle of deer to deer and deer to cattle transmission. Deer were vaccinated with the human TB vaccine, BCG, and vaccine protection evaluated. Disease was less severe in deer receiving 2 doses of BCG compared to unvaccinated deer. BCG vaccination of deer can provide some protection against development of tuberculosis and spread of disease to other deer or to domestic animals. This information will be useful to wildife health officials, livestock health officials and USDA action agencies such as USDA/APHIS.

Technical Abstract: Wildlife reservoirs of Mycobacterium bovis represent serious obstacles to the eradication of tuberculosis in domestic livestock. In Michigan, USA tuberculous white-tailed deer transmit M. bovis to cattle. One approach in dealing with this wildlife reservoir is to vaccinate deer in order to 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 doses of 10**7 CFU of M. bovis BCG (n=11); 1 SC dose of 10**7 CFU of M. bovis BCG (n=10); and unvaccinated deer (n=10). After vaccination, deer were inoculated intratonsilarly with 300 CFU of virulent M. bovis. Gross lesion severity scores of the medial retropharyngeal lymph node were significantly reduced in deer receiving 2 doses of BCG compared to non-vaccinated deer. Vaccinated deer had fewer lymph node granulomas than unvaccinated deer, and most notably, fewer late stage granulomas characterized by coalescent caseonecrotic granulomas containing numerous acid-fast bacilli. BCG was isolated from 7/21 vaccinated deer as long as 249 days after vaccination. In one case BCG was transmitted from a vaccinated deer to an unvaccinated deer. In white-tailed deer BCG Pasteur provides measurable protection against challenge with virulent M. bovis. However, persistence of vaccine within tissues as well as shedding of BCG from vaccinates remain areas for further investigation.