From Science:
Researchers have developed a way to vaccinate mice against deadly prion diseases, which include scrapie, kuru, mad cow disease, and Creutzfeldt-Jakob disease. The findings, presented today at the annual American Academy of Neurology meeting in Boston, suggest that these degenerative brain diseases can be stopped if caught early enough.
Searching for a more effective vaccine, a team led by neuropathologist Thomas Wisniewski of the New York University School of Medicine in New York City took a new approach. They genetically modified a strain of Salmonella bacteria to express prion proteins. When researchers fed these bacteria to mice, the bugs multiplied in the rodents’ guts, and the animals developed antibodies against the prions. A month later, the researchers fed the mice disease-causing prions; mice that had developed antibodies against the prion proteins stayed healthy for the remainder of the study, 400 days, while those not inoculated with the modified Salmonella developed a degenerative brain disease, like mad cow disease, and died within 200 days.
More here.