Image caption MRI brain scan showing multiple sclerosis lesions

An anti-tuberculosis vaccine could prevent multiple sclerosis, early research suggests.

A small-scale study by researchers at the Sapienza University of Rome has raised hopes that the disease can be warded off when early symptoms appear.

More research is needed before the BCG vaccine can be trialled on MS patients.

The MS Society said the chance to take a safe and effective preventative treatment after a first MS-like attack would be a huge step forward.

MS is a disease affecting nerves in the brain and spinal cord, causing problems with muscle movement, balance and vision.

Early signs include numbness, vision difficulties or problems with balance.

BCG vaccine Bacillus Calmette-Guerin (BCG) is a live vaccine made up of a weakened strain of Mycobacterium bovis, a bacterium that causes tuberculosis (TB) in cattle

a bacterium that causes tuberculosis (TB) in cattle The bacteria are altered so that they do not cause a TB infection, but stimulate the body's immune system to make it resistant to the disease

The vaccine has existed for 80 years and is one of the most widely used of all current vaccines, reaching more than 80% of newborns and infants in countries where it is part of the national childhood immunisation programme

About half of people with a first episode of symptoms go on to develop MS within two years, while 10% have no more problems.

In the study, published in the journal Neurology, Italian researchers gave 33 people who had early signs of MS an injection of BCG vaccine.

The other 40 individuals in the study were given a placebo.

After five years, 30% of those who received the placebo had not developed MS, compared with 58% of those vaccinated.

"These results are promising, but much more research needs to be done to learn more about the safety and long-term effects of this live vaccine," said study leader Dr Giovanni Ristori.

"Doctors should not start using this vaccine to treat MS or clinically isolated syndrome."

Dr Susan Kohlhaas, head of biomedical research at the MS Society, said it was a small but interesting study.

"It's really encouraging to see positive results from this small trial, but they'll need validating in larger and longer-term studies before we know if the BCG vaccination can reduce the risk of someone developing MS.

"Ultimately, the chance to take a safe and effective preventative treatment after a first MS-like attack would be a huge step forward."

The findings add weight to a theory that exposure to infections early in life might reduce the risk of diseases such as MS by stimulating the body's immune system.

Dr Dennis Bourdette, of Oregon Health and Science University in Portland, US, said the research suggested "BCG could prove to be a 'safe, inexpensive, and handy' treatment for MS".

He wrote in an accompanying editorial in Neurology: "The theory is that exposure to certain infections early in life might reduce the risk of these diseases by inducing the body to develop a protective immunity."