Might a vaccine to prevent tuberculosis offer protection against multiple sclerosis as well?

A new study in the journal Neurology focused on 82 adults (average age, 32) at high risk for developing MS because they had had an episode involving numbness, vision problems, or balance problems and an MRI scan suggestive of MS. They were randomly assigned to be injected with the bacille Calmette-Guerin (BCG) vaccine for TB or a placebo within 90 days of that episode. After six months, all participants took the MS drug interferon beta-1a (Avonex) for a year and then took whatever MS drug their doctors prescribed.

Brain scans six months after vaccination showed fewer lesions among those who had been given the BCG vaccine. After five years, 58 percent of those given the vaccine had experienced no further episodes, compared with 30 percent who got the placebo. No major side effects were reported.

In MS, the immune system attacks the body rather than acting as its defense system, but its cause remains unknown. Among the study's caveats: it did not show how the BCG vaccine works against MS; and it was too brief to assess long-term safety. - Washington Post