In 1868, French physician Jean-Martin Charcot, known as the founder of modern neurology, defined a disease entity in which multiple plaques formed in the brain and spinal cord, with varying physical symptoms, called Sclérose en plaques, or in English as multiple sclerosis (MS). Today, it is known as a chronic autoimmune and neurodegenerative disease in which the body's immune system attacks its own tissues over time.
The exact underlying cause of this incurable and disabling disease of the central nervous system remained somewhat of a mystery for more than a century and a half. But recent new research has provided strong evidence that the common Epstein-Barr virus (EBV) is a trigger for MS.
The linking of MS and EBV could be a significant step in gaining the upper hand in the prevention of MS, which affects nearly 1 million people over the age of 18 in the United States.
The National MS Society said development of EBV vaccines is underway with an aim of reducing the number of people who suffer with MS.
MS facts
You may remember from high school biology class that our central nervous systems are made up of the brain, spinal cord and optic nerves. In people with MS, the body's immune system mistakes the central nervous system for the enemy and responds by attacking by the protective sheath (myelin) that covers nerve fibers. The resulting damage interferes with the transmission of nerve signals between the central nervous system and other parts of the body.
The MS Society says symptoms are unpredictable and vary from one person to another and in the same person over time.
The most common symptoms include fatigue, numbness and tingling, blurred vision, double vision, weakness, poor coordination, imbalance, pain, depression and problems with memory and concentration.
Although anyone can get MS, more than twice as many women as men develop the disease and this gender disparity has been increasing over the past half century.
It occurs in most ethnic groups but is most common in white people of northern European ancestry.
A combination of genetics and environmental factors appears to increase the risk of getting MS, although there is no evidence that it is directly inherited. Factors such as low vitamin D and cigarette smoking have been shown to increase the risk.
While the exact cause of MS has been murky at best, scientists have for years suspected that EBV infection is somehow involved. Until recently, a causal connection has been hard to establish.
What is Epstein-Barr virus?
Epstein-Barr is a type of herpes virus spread primarily through contact with infected saliva. Sometimes referred to as the kissing virus, it is best known as the cause of infectious mononucleosis.
It is common. Most people are infected with EBV during childhood, typically without harm. However, EBV infection in adolescence and adulthood can cause infectious mononucleosis. Once infected, EBV stays in the body throughout a person's lifetime.
In early 2022, Harvard Medical School researchers reported the results of a large 20-year study revealing MS may be triggered by EBV infection. Those with EBV infection were found to have significantly increased odds of developing MS compared to those who were not infected. This led the researchers to conclude that EBV is the leading cause of MS.
The researchers also discussed that it's important to note that while 95% of adults are estimated to have been infected with EBV, only a very small number go on to develop MS. Therefore, EBV is a necessary trigger, but by itself alone is not sufficient to cause MS.
They also noted that it's possible that an EBV vaccine could help to prevent MS, or that studies of the virus could lead to new MS treatment pathways. More research regarding these leads are ongoing.
The National Institute of Allergy and Infectious Diseases is involved in an early-stage clinical trial for a vaccine to prevent EBV. The trial is expected to be completed in four years.
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