The Epstein-Barr virus (EBV) causes mono, also known as the “kissing disease.” Now scientists believe that the virus may lead to multiple sclerosis.

A disease of the brain and spinal chord that can cause paralysis, cognitive dysfunction and other debilitating symptoms, multiple sclerosis affects roughly 2.5 million people and a total 200 new cases are diagnosed each week within the U.S.

“It’s probably a bold statement, but it’s likely to be true that almost all autoimmune diseases are triggered by a microbe, usually a virus,” Dr. Lawrence Steinman, a neurology and MS expert at Stanford, told Insider.

Christian Denis, now 39, believes he and his girlfriend both had mono back in 1999. After being debilitated by the kissing disease for nearly a year, Denis suffered a whole new bevy of symptoms three years later. At 19, he suffered double vision, trouble pointing, lifting and grabbing things. Soon after, he was diagnosed with multiple sclerosis.

He now takes a dozen pills a year to aid with his multiple sclerosis, and he uses a wheelchair to get around. “The idea of it sounds amazing,” Denis said when asked about the possibility of ending multiple sclerosis.

Using health data from more than 10 million U.S. military members, Harvard professor Alberto Ascherio estimates the risk of developing multiple sclerosis increased 32-fold after an EBV infection. By culling the spread of EBV, scientists may be one stope closer to making multiple sclerosis a thing of the past.

“This is a big step because it suggests that most MS cases could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure for MS,” Ascherio said in a press release.

Leading scientists, including Ascherio, believe a mono vaccine could be the next big thing for combatting multiple sclerosis. But there is still much more work to be done.