HOST SPECIES DIFFERENCES IN RESPONSES TO BRUCELLA OR MYCOBACTERIUM VACCINES

Authors: Olsen, Steven; Stoffregen, William

Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/4/2005
Publication Date: 12/4/2005
Citation: Olsen, S.C., Stoffregen, W.C. 2005. Host species differences in responses to brucella or mycobacterium vaccines [abstract]. Research Workers in Animal Diseases Conference Proceedings. p. 99.

Interpretive Summary: Brucella abortus is a disease that causes abortion and associated economic losses in infected cattle herds. The persistence of Brucella abortus in wildlife reservoirs pose a risk to the completion of the Brucellosis Eradication Program for cattle. Understanding the species differences in immunologic responses to brucellosis vaccination will assist in developing new protective vaccines against brucellosis for domestic livestock and wildlife. In a series of studies, we identified immunologic differences between cattle, where brucellosis vaccination is effective, and wildlife reservoirs where vaccination is not as effective. Immunologic differences between species assist in understanding differences in protection against brucellosis. This data will be of benefit to the National Park Service, the Animal and Plant Health Inspection Service, and the states of Montana, Wyoming, and Idaho in their efforts to resolve the brucellosis problem caused by wildlife reservoirs of brucellosis. Improvement in brucellosis vaccines as a result of this work will help prevent transmission of brucellosis to cattle herds and assist in the completion of the Brucellosis Eradication Program.

Technical Abstract: Eradication of brucellosis and tuberculosis from livestock populations is a high priority for regulatory personnel. Persistence of these diseases in wildlife reservoirs pose a substantial risk for transmission to livestock. In a series of studies, immunologic responses of wildlife species of interest to brucellosis and/or mycobacterium vaccines were characterized and compared to responses of cattle. As cell-mediated immunity is critical for long-term protection against diseases caused by intracellular bacteria, our studies particularly focused on proliferative responses of peripheral blood mononuclear cells (PBMC), alpha-interferon production, and flow cytometric analysis of proliferating PBMC subsets. Our data suggests that immunologic responses to Brucella or Mycobacterium vaccines differ by species. Species that are considered to be closely related may demonstrate significant differences in immunologic responses to vaccination. Our data also suggests that immunologic responses to vaccination cannot be predicted but must be evaluated in the species of interest. Particularly in elk, immunologic responses to Brucella and Mycobacterium vaccines include robust antibody and deficient cell-mediated responses and might be a valuable model for characterizing the role of humoral responses in disease models.