Chances for a Multiple Sclerosis Vaccine
Multiple sclerosis (MS) is a mysterious disease that continues to baffle experts in all areas, from prevention to diagnosis, treatment, and prognosis. That’s one reason why the new discovery that a tuberculosis vaccine may prevent development of MS is an occasion for guarded optimism.
Previously I reported on some potential new ways to diagnose MS, including the use of magnetic resonance imaging (MRI) to look for deposits of iron in the brain’s gray matter. Such accumulations appear to be a sign of early disease.
Now a group of Italian researchers suggest that giving a type of TB vaccine to individuals who demonstrate early signs of multiple sclerosis such as balance problems, trouble with vision, and numbness may help stop the disease in some people. The vaccine is known as Bacille Calmette-Guerin (BCG).
BCG vaccine is most often used outside the United States in countries where there is a high prevalence of tuberculosis. Although it is not generally administered in the states, it may be recommended for specific individuals who meet certain criteria.
Why is the BCG vaccine not commonly given in the United States? According to the Centers for Disease Control and Prevention, it has “variable effectiveness” against adult TB, it can interfere with the reactivity of the tuberculin skin test, and there is a low risk of infection in the states.
What the MS study showed
A total of 73 people who had experienced a single episode of symptoms associated with MS were enrolled in the study. Thirty-three individuals were given the vaccine while 40 received a placebo.
All the participants underwent a monthly brain scan for six months and then were treated with interferon beta-1a, a drug commonly used to treat MS patients, for 12 months. The investigators followed the patients for five years.
Here is what the investigators found:
- On average, individuals who received placebo had more than twice the number of brain lesions (which are characteristic of MS) than did those who received the vaccine
- At the end of five years, 42 percent of individuals in the vaccine group had developed MS while 70 percent of those in the placebo group had the disease. Generally, about 50 percent of people who show early signs of the disease go on to develop MS within two years.
- No side effects were associated with the vaccine
According to Dr. Giovanni Ristori of Sapienza University in Rome, where the study was conducted, more research on the use of this vaccine is needed. He warned that doctors should not use the TB vaccine to treat anyone who has MS or its early signs.
Although this study did not lead to a vaccine for MS, it has opened the door to the possibility. We may be closer to a vaccine for multiple sclerosis than we were before.
Centers for Disease Control and Prevention
Ristori G et al. Effects of bacilli calmette-guerin after the first demyelinating event in the CNS. Neurology 2013 Dec 4. Epub before print