Multiple sclerosis, often called MS, is a serious disease that affects the brain and spinal cord. It happens when the body’s immune system attacks its own nerve cells by mistake.
Over time, this damage affects how the brain sends signals through the body. People with MS may have problems with movement, vision, balance, and thinking. In more severe cases, the disease can lead to long-term disability and even shorten life.
Around 2.8 million people worldwide are living with MS. For many years, scientists have tried to understand what causes this disease, but the answer has not been clear. Many factors have been suggested, including genetics and environmental triggers, but no single cause had been proven.
Now, a major study from Harvard University has provided strong evidence that a very common virus may be the main cause of MS. The virus is called Epstein-Barr virus, or EBV.
EBV is extremely common. About 95% of adults around the world have been infected with it at some point in their lives. It is best known for causing infectious mononucleosis, also called “mono” or the “kissing disease.” After infection, the virus stays in the body for life, usually in an inactive form.
Because EBV is so common, it has been difficult for scientists to prove that it causes MS. Most people who have EBV never develop MS, and the symptoms of MS often appear many years after the infection. This long delay has made it hard to study the connection.
In this new research, scientists used a very large and detailed set of data to solve this problem. They studied more than 10 million young adults who were serving in the United States military. These individuals regularly gave blood samples as part of their service, which allowed researchers to track infections over time.
Among these millions of people, 955 were later diagnosed with MS. The researchers carefully examined their blood samples, which had been collected every two years, to see when they became infected with EBV and how that related to the development of MS.
The findings were very clear. The risk of developing MS increased by 32 times after a person became infected with EBV. This was a very strong increase in risk. In comparison, infections with other viruses did not show any meaningful link to MS.
The researchers also looked at a marker in the blood called neurofilament light chain. This substance is released when nerve cells are damaged. They found that levels of this marker increased only after EBV infection, which suggests that the virus may trigger the early stages of nerve damage seen in MS.
These results strongly support the idea that EBV is not just linked to MS, but is likely the main cause of the disease. The researchers believe that after EBV infection, the immune system may slowly change over time. This process could eventually lead to the immune system attacking the body’s own nerves.
The long gap between infection and symptoms may be because the disease develops slowly and quietly at first. Damage may begin years before a person notices any clear signs of MS.
This discovery is very important because it opens up new ways to prevent and treat MS. At the moment, there is no way to prevent EBV infection, and there is no cure for MS. However, if EBV is the main cause, then stopping the virus could prevent many cases of the disease.
In the future, scientists may be able to develop vaccines to protect people from EBV. They may also create antiviral treatments that target the virus in people who are already infected. These approaches could reduce the risk of MS or even stop the disease from developing.
The study was led by Alberto Ascherio and published in the journal Science. It is one of the strongest pieces of evidence so far linking a virus to a major chronic disease.
While more research is still needed, this discovery gives new hope to millions of people affected by MS. It suggests that a disease that once seemed mysterious may have a clear and preventable cause.
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