12/05/2013 08:40 am ET

TB Vaccine Might Help Prevent Multiple Sclerosis, Study Suggests


A tuberculosis vaccine used in other parts of the world seemed, in a small new study, to be effective at preventing multiple sclerosis among people showing early signs of the condition.

People showing early signs of multiple sclerosis -- a situation called clinically isolated syndrome -- who were randomized to received the Bacille Calmette-Guérin vaccine before undergoing multiple sclerosis treatment were less likely to develop multiple sclerosis, compared with those who received a placebo. The vaccine is used in other countries for tuberculosis prevention, though it is not used in the United States.

Specifically, 58 percent of people who received the vaccine before taking the multiple sclerosis drug interferon beta-1a for a year, followed by a doctor-recommended multiple sclerosis drug, did not develop multiple sclerosis after five years. Comparatively, just 30 percent of people who did not receive the vaccine did not develop multiple sclerosis after five years.

Plus, there were no side effects noted during the study, nor were there any differences in side effects between those who received the vaccine and those who did not.

While researchers noted that the results were promising, more studies are needed "to learn more about the safety and long-term effects of this live vaccine," study researcher Dr. Giovanni Ristori, M.D., Ph.D., of Sapienza University of Rome, said in a statement. "Doctors should not start using this vaccine to treat MS or clinically isolated syndrome."

The Neurology study included 73 people with early signs of multiple sclerosis, as indicated through an MRI, as well as symptoms like balance problems, numbness and vision problems. (Researchers noted that about half of people with these early signs will go on to develop multiple sclerosis in two years, while another 10 percent will not go on to develop any more multiple sclerosis-related problems.)

The exact causes of multiple sclerosis are not known, though the condition might be linked somehow to an infectious agent, according to the National Multiple Sclerosis Society. The Epstein-Barr virus has been named the "most promising candidate" in the disease, though there is not yet any scientific confirmation that this virus triggers multiple sclerosis. Genetics are also thought to play a role, since the condition is more common among women than men; the National Institutes of Health noted that it could be an autoimmune disease.