Multiple sclerosis (MS) is a chronic disease of the central nervous system. It is an unpredictable condition that can be relatively mild, disabling, or devastating. Some individuals with MS may be minimally affected, while others may lose their ability to see clearly, write, speak, or walk when communication between the brain and other parts of the body becomes disrupted. A new study has found that a vaccine used to prevent tuberculosis (TB) holds promise for the prevention of MS in individuals when the first symptoms of the disease appear. Italian researchers published their findings online on December 4 in Neurology, the medical journal of the American Academy of Neurology.
The study group comprised 73 individuals who had a first episode that was suggestive of MS (i.e., numbness, vision problems, or problems with balance); in addition, the subjects underwent magnetic resonance imaging that revealed signs of possible MS. Approximately 50% of the subjects developed MS within two years, while 10% did not experience any more episodes over the two years. A live vaccine, Bacille Calmette-Guérin, was given to 33 of the subjects. The vaccine is administered in other nations to prevent tuberculosis; however it is not used for that purpose in the United States. The remaining 40 participants received a placebo injection. All of the subjects underwent a brain scan once a month for six months. Then, they were given the MS medication interferon beta-1a for a year. Subsequently, they took the MS drug recommended by their neurologist. The participants were followed for five years to determine whether they developed definite MS.
A difference between the two groups was noted six months after the onset of the study. The individuals who received the vaccine had fewer brain lesions that suggested MS than those who received the placebo. Three lesions were found among the vaccinated individuals and seven lesions were found among the unvaccinated. At the conclusion of the study, 58% of the vaccinated individuals had not developed MS, compared to 30% of those who received the placebo injection.
The researchers noted that no major side effects occurred during the study. In addition, no difference in side effects was found between those who received the vaccine and those who did not. “These results are promising, but much more research needs to be done to learn more about the safety and long-term effects of this live vaccine,” explained study author Giovanni Ristori, MD, PhD, of Sapienza University of Rome in Italy. He added, “Doctors should not start using this vaccine to treat MS or clinically isolated syndrome.”
Dennis Bourdette, MD, of Oregon Health & Science University in Portland and a Fellow of the American Academy of Neurology wrote an accompanying editorial. He noted that the study results provide support to the “hygiene hypothesis” that, compared to Africa, South America, and parts of Asia, a higher level of sanitation and use of disinfectants and antibiotics may account for some of the increased rate of MS and other immune system diseases in North America and much of Europe. The premise is that exposure to certain infections early in life might reduce the risk of these diseases by inducing the body to develop a protective immunity.
The study was supported by the Italian Ministry of Health, the Center for Experimental Neurological Therapies and S. Andrea Hospital in Rome, Sapienza University of Rome, Don Carlo Gnocchi Foundation in Milan, and Federico II University in Naples.
More information about MS is available at this link.