The Latest Research on the Epstein-Barr Virus and MS

Multiple sclerosis (MS) is a disease that affects almost 1 million people in the United States alone. Doctors do not know what causes MS. But they do have many ideas about the cause.¹

One theory is that MS is caused by the Epstein-Barr virus (EBV). EBV is a common virus. It causes the infection that most people know as mono or mononucleosis. EBV has also been linked to several types of cancer.²

Investigating the link between EBV and MS

Doctors wanted to find out if EBV causes MS. They looked at the medical records of more than 10 million military personnel. For 20 years, doctors have been screening members of the military for HIV. Any blood left over after HIV screening is stored for future testing. This extra blood was tested for EBV.²

Doctors looked at the number of military members who developed MS. There were 801 with MS who had corresponding blood samples. Of the 801 military members with MS, 800 of them had an EBV infection at least 5 years before they developed MS. This means that only 1 person who had MS was not infected with EBV at some point in their life.³

MS and other viruses

Doctors also ran tests to find out if the people with MS had been infected by other common viruses. They looked at another common virus called cytomegalovirus (CMV). There was not a link between CMV and MS.^2,3

What does this mean for MS research?

It is important to remember that association does not equal causation. That is, just because scientists have found a link between EBV and MS, it does not mean that EBV causes MS.²

Yes, EBV is linked with MS. But almost 95 percent of people who are infected with EBV will not go on to have MS. Doctors can now focus their research on how EBV contributes to MS:³

• B cells: Doctors know that EBV infects a part of the immune system known as B cells. B cells are some of the few cells in the body that can cross from the blood into the brain. Doctors think this may be part of how EBV is linked to MS. They are continuing to research if and how that might be so.
• Immunity: Doctors think EBV may teach the immune system to attack the nerves.
• Genetics: Doctors will also be researching if there is a genetic factor in how some people who have been exposed to EBV go on to develop MS. It appears that there may be a genetic link to MS.

Possibility for new treatments

If EBV is a factor that leads to MS, it may help doctors find new treatments. There is currently a vaccine in progress for EBV. A successful EBV vaccine could prevent people from getting EBV at all or at least keep infections mild.²

Doctors also want to know if treating active EBV infections with antiviral drugs would help reduce the number of MS cases. If doctors can find better treatments for EBV, they may be able to stop MS from developing.³

New developments in research such as the link between MS and EBV are exciting. While these new developments do not show us exactly what causes MS, they do help doctors know where to focus future research. It may feel a little frustrating when research seems to cause more questions than answers. It is important to remember that studies like these are the best step in finding better treatment and prevention for MS.