PARTIAL PROTECTION IN BALB/C HOUSE MICE () AND ROCKY MOUNTAIN ELK () AFTER VACCINATION WITH A KILLED, MUCOSALLY DELIVERED VACCINE.

Brucellosis, caused by , has been eliminated from livestock in the US. Remaining wildlife reservoirs are the bison () and elk () populations in Yellowstone National Park and the surrounding area, from which there is periodic exposure and transmission to surrounding livestock herds. Elk account for nearly all of the livestock exposure, and the infection appears to be expanding in the elk population. Currently, there are no known effective vaccines for brucellosis in elk. We conducted three experiments to evaluate the efficacy and practicality of delivering a killed vaccine compounded with montmorillonite clay as a carrying agent to oral, nasal, and conjunctival mucosa. The first study, conducted in laboratory mice (), demonstrated protection against infection equal to that produced by the currently approved cattle () vaccine RB51. The second experiment, conducted as a pilot study in a small sample of elk, demonstrated partial protection against infection. Results of the third experiment showed that elk consumed the majority of a surrogate vaccine compounded with montmorillonite mixed in hay with oral, nasal, conjunctival, and gastrointestinal exposure to the vaccine. These results suggest that multiple exposures to a mucosally delivered vaccine may provide an effective method of vaccinating wildlife.