Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 8, 2006
Publication Date: June 8, 2006
Citation: Palmer, M.V., Thacker, T.C., Waters, W.R. 2006. Vaccination of white-tailed deer with Mycobacterium bovis bacillus Calmette Guerin (BCG). [abstract]. In: Michigan Bovine Tuberculosis 11th Annual Meeting, June 7-8, 2006, Lansing, Michigan, 2006 CDROM. Technical Abstract: In 1994, a focus of M. bovis infection in white-tailed deer was identified in Michigan. This represents the first known reservoir of M. bovis in free-ranging wildlife in the United. Current control measures include decreasing deer density and limitations on feeding and baiting of deer. Another possible control measure would be vaccination of deer to prevent disease transmission. To evaluate the efficacy of M. bovis BCG vaccination of white-tailed deer, 31 yearling white-tailed deer were randomly assigned to one of three groups; 2 doses of 10**7 CFU of BCG (Pasteur) administered 6 weeks apart SC (n=11); 1 dose of 10**7 CFU of BCG (Pasteur) SC (n=10) and unvaccinated deer (n=10). All deer were inoculated with 300 CFU of virulent M. bovis 77 days after the 2 dose BCG group received the second dose of vaccine. One hundred thirty days after challenge all deer were euthanized and examined. Gross lesion severity scores of the medial retropharyngeal lymph node were reduced (P < 0.05) in deer receiving 2 doses of BCG compared to unvaccinated deer. Microscopic evaluation of the medial retropharyngeal lymph nodes revealed fewer granulomas in BCG-vaccinated deer than in unvaccinated deer. Moreover, medial retropharyngeal lymph node granulomas in deer receiving 2 doses of BCG were smaller, less necrotic with rare acid fast bacilli compared to lesions in lymph nodes from deer receiving a single dose of BCG or unvaccinated deer. Mycobacterium bovis BCG (Pasteur) can be effective in reducing lesion severity in M. bovis-inoculated deer. Decreased lesion severity with less necrosis and fewer acid fast bacilli would likely decrease the ability of vaccinated deer to shed virulent M. bovis thus decreasing intraspecies and interspecies transmission.