A lack of exposure to infections early in life is one of many proposed contributing factors to development of multiple sclerosis (MS). With this in mind, some have questioned whether giving the immune system a light workout could stave off the autoimmune disorder. New data from Italy suggests they might be on to something.
The data comes from a trial of 73 patients who showed early signs of MS, such as imbalance, numbness and vision problems. Almost half of the participants were given one dose of the tuberculosis vaccine Bacille Calmette-Guérin (BCG) vaccine, while the rest received a placebo. After 5 years, 58% of those who received the vaccine had not developed MS, compared to 30% in the placebo group. Typically, 50% of people develop 'clinically definite' MS within two years of showing symptoms, while 10% remain unchanged.
Although the trial is small and far from conclusive, the potential of the approach has caught the attention of MS researchers. "Ultimately, the chance to take a safe and effective preventative treatment after a first MS-like attack would be a huge step forward," the MS Society's head of biomedical research Dr. Susan Kohlhaas told the BBC. A larger study is needed to show if the tuberculosis vaccine is definitely helping to prevent the early signs of MS from developing into a full blown autoimmune disorder.
Even so, the data adds weight to the 'hygiene hypothesis,' a theory that links development of MS to a lack of exposure to infections early in life. If the theory is correct, BCG or other cheap, well-tolerated vaccines could help prevent MS.