The tuberculosis vaccine could help prevent multiple sclerosis (MS) in people showing early signs of the disease, research suggests.
The Bacille Calmette-Guerin (BCG) jab, whichwas given to millions of Britons as part of a now-defunct NHS vaccination programme, appears to double the chance of patients not developing MS.
The research, published in the journal Neurology, showed that 58% of vaccinated people did not develop MS, compared with 30% of those who received a dummy drug.
However, the authors warned that more research was needed and said it was unclear how long the vaccine might offer protection.
The study involved 73 people who suffered an episode of symptoms that could suggest MS, such as numbness, vision problems or issues with balance. They also had an MRI scan that showed signs of possible MS.
Experts know that around half of people with these symptoms develop full MS within two years, while one in 10 go on to have no more problems.
For the study, 33 of people received the BCG vaccine and the rest received a placebo, then all of the participants had brain scans once a month for six months.
Both groups then received the MS drug interferon beta-1a for a year, followed by any drugs recommended by their neurologist.
Researchers evaluated the results of the study five years after it began. After the first six months, the people who received the vaccine had an average of three of the brain lesions that are signs of MS, compared with seven for those who received the placebo.
The subjects experienced no major side effects during the study.
Study author Giovanni Ristori, from the Sapienza University of Rome, said: “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.
“Doctors should not start using this vaccine to treat MS or clinically isolated syndrome (early symptoms).”
MS is a neurological condition which affects around 100,000 people in the UK.
Most people are diagnosed between the ages of 20 and 40, and it is around three times as common in women as men.
High-profile sufferers include TV personality Jack Osbourne. Susan Kohlhaas, head of biomedical research at the MS Society, said: “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.”
In an editorial accompanying the study, Dennis Bourdette, from Oregon Health and Science University in Portland, said the results supported the “hygiene hypothesis”.
This is that better sanitation and use of disinfectants and antibiotics might account for some of the increased rate of MS and other immune system diseases in North America and much of Europe.