Vaccine prevents prion disease in mice

May 03, 2007

An oral vaccine can prevent mice from developing a brain disease similar to mad cow disease, according to research that will be presented at the American Academy of Neurology's 59th Annual Meeting in Boston, April 28 – May 5, 2007. Prion diseases, which include scrapie, mad cow disease, and chronic wasting disease, are fatal and there is no treatment or cure.

The disease spreads when an animal eats the body parts of other animals contaminated with prions. The disease causes dementia and abnormal limb movements.

Prion is a protein that is also an infectious agent. The proteins are so similar to proteins found normally that the immune system does not fight them off. To develop a vaccine that would stimulate the mice's immune system, researchers attached prion proteins to a genetically modified strain of Salmonella.

For the study, the mice were orally vaccinated with a safe, attenuated Salmonella strain, which expressed the prion protein. Then they were divided into two groups – those who had high levels of antibodies in their blood and thus responded well to the vaccine and those with low levels of antibodies.

The mice with high levels of antibodies had no symptoms of the disease after 400 days. The mice with low levels of antibodies also had a significant delay in the onset of the disease. It normally takes 120 days for mice that have not been vaccinated to develop the disease.

"These are promising findings," said study author Thomas Wisniewski, MD, of NYU School of Medicine in New York, and a member of the American Academy of Neurology. "We are now in the process of redesigning the vaccine so it can be used on deer and cattle."

Wisniewski said much more work is needed before the vaccine could be considered for humans. "The human version of prion disease usually occurs spontaneously and only rarely because of eating contaminated meat," he said. "But if, for example, a more significant outbreak of chronic wasting disease in deer and elk occurs and if it were transmissible to humans, then we would need a vaccine like this to protect people in hunting areas."

He also noted that a vaccine that decreases the spread of prion disease in animals also reduces the possibility that the disease could infect humans.

Source: American Academy of Neurology

Explore further: Oral contraceptive equal to antibiotics for acne care

add to favorites email to friend print save as pdf

Related Stories

Battling chronic wasting disease in elk and deer

Sep 27, 2011

Chronic wasting disease (CWD) has been responsible for the severe decline of Saskatchewan’s game farm industry. Millions have been spent on programs to screen herds and compensate farmers.

Recommended for you

Oral contraceptive equal to antibiotics for acne care

3 hours ago

(HealthDay)—At six months, oral contraceptive pills (OCPs) are comparable to systemic antibiotics for acne management, according to a review published in the September issue of the Journal of the American Ac ...

Photodynamic therapy vs. cryotherapy for actinic keratoses

4 hours ago

Photodynamic therapy (PDT, which uses topical agents and light to kill tissue) appears to better clear actinic keratoses (AKs, a common skin lesion caused by sun damage) at three months after treatment than cryotherapy (which ...

US official warns Ebola outbreak will get worse

6 hours ago

A third top doctor has died from Ebola in Sierra Leone, a government official said Wednesday, as a leading American health official warned that the outbreak sweeping West Africa would get worse before it ...

UN releases $1.5mn to help DR Congo fight Ebola

8 hours ago

The United Nations on Wednesday allocated $1.5 million (1.1 million euros) to help the Democratic Republic of Congo fight Ebola, just days after the country confirmed its first cases this year.

User comments : 0