A December 4, 2013 report in the online version of the journal Neurology discusses some very promising work regarding multiple sclerosis (MS). It may be possible, the authors say, for a tuberculosis vaccine to prevent this devastating disease if the symptoms are caught early enough.
Multiple sclerosis is a chronic, and often disabling disease. In this disease, a person’s own immune system begins attacking their brain, spinal cord and optic nerves, damaging a fatty substance called myelin which coats and protects nerve fibers, as well as the nerve fibers themselves. The severity, progression and specific symptoms which an individual may experience are quite variable and may range from mild to severe. Symptoms may include numbness in the limbs, paralysis or vision loss.
Seventy-three people participated in the study. They were selected for the project because they had had a first episode of MS-like symptoms – such as numbness, balance issues and vision problems – as well as a magnetic resonance imaging (MRI) scan showing potential signs of the disease. Statistics show that half of people who meet this set of criteria – called clinically isolated syndrome – will develop MS within the next two years. However, 10 percent of people with this cluster of symptoms will never experience any further problems.
Thirty-three of these individuals were given a single injection of a live vaccine called Bacille Calmette-Guérin. This vaccine is often used in various countries with high rates of tuberculosis as a preventative for this disease. All other study participants were administered an inactive placebo injection.
All of the participants were given monthly brain scans for a period of six months. Then, they receive an MS medication called interferon beta-1a for a year. Afterwards, the were given whatever MS medication that was recommended by their neurologist. They were followed for a total of five years after the onset of the study to see if they developed definite MS.
After the initial six months, the people who were given the vaccine appeared to be doing better, having fewer brain lesions than those in the placebo group. In addition, by the time the study ended, 58 percent of those who received the vaccine had not developed MS. In contrast, only 30 percent of those who received the placebo had not developed the disease.
Neither the vaccine-treated group nor the placebo group developed any major side effects during the course of the study.
In an editorial published in the same journal, Dr. Dennis Bourdette commented that the results of this study lend credence to what is known as the “hygiene hypothesis.” This hypothesis makes the argument that rates of MS have increased in recent times due to the extensive use of antibiotics and disinfectants. The theory goes, according to Dr. Bourdette, that exposure to infections childhood could prevent immune-based diseases such as MS by creating immunity in the body. However, we have become so “clean” as a society that people are not having the opportunity to be exposed to organisms which would induce this immunity.
Study author Dr. Giovanni Ristori notes that, while the findings of this study are quite promising, doctors should not start treating MS or clinically isolated syndrome with the tuberculosis vaccine. There is much more research that needs to be done, he says, in order to learn about how safe this treatment is in the long-term.
By Nancy Schimelpfening