New deer vaccine against mad-cow-like disease may help people too

A white-tailed deer--Courtesy of Scott Bauer, USDA

A team led by scientists at New York University's Langone Medical Center announced on Sunday that they have successfully vaccinated five deer against chronic wasting disease (CWD)--an illness related to the human brain disorder Creutzfeldt-Jakob disease. The discovery could have wide-ranging applications to research into new treatments and vaccines for human diseases caused by "prions," or misfolded proteins. The most famous of those is bovine spongiform encephalopathy (BSE), better known as mad cow disease, which was linked to an outbreak of Creutzfeldt-Jakob disease in the United Kingdom 20 years ago.

The study, published online in the journal Vaccine, involved a vaccine made from Salmonella bacteria, which can easily infiltrate the gut, much like many prions do via contaminated food. The scientists inserted a prionlike protein into the genome of an attenuated, or weakened, form of Salmonella. This induced an immune response in the gut of the deer, who were exposed to prion-infected brain tissue. Their stomachs then produced antibodies that destroyed the prions.

"Although our anti-prion vaccine experiments have so far been successful on mice and deer, we predict that the method and concept could become a widespread technique for not only preventing, but potentially treating many prion diseases," said lead study investigator and associate NYU professor Fernando Goni in a press release from the college.

CWD is a major risk to deer in North America, affecting as many as 100% of captive animals and large numbers of wild deer and related animals such as moose, elk and caribou, according to the release. Livestock producers have expressed concern that the disease could spread to nearby cattle, much like BSE spread through the U.K., inducing widespread panic in the international beef industry and among consumers.

Mad cow disease was linked to 177 fatal cases of Creutzfeldt-Jakob in the U.K., according to statistics quoted by the Daily Mail. When the disease peaked in 2000, 28 British citizens died after eating beef contaminated with tissue from cows that were infected with BSE, the paper says.

The members of the NYU study team believe that if their vaccine proves effective in further studies, as few as 10% of animals in any given deer population would need to be inoculated to induce herd immunity.

What's more, the science behind the vaccine could prove applicable to many human diseases aside from Creutzfeldt-Jakob that are believed to be related to prions. They include kuru, familial insomnia, variably protease-sensitive prionopathy, and perhaps even Alzheimer's disease, which recent research suggests may be associated with protein misfolding.

- here's the press release
- access an abstract of the study here
- get more at the Daily Mail