An estimated 2.8 million people around the world have multiple sclerosis (MS), an autoimmune disease in which the immune system damages the brain and spinal cord.
Symptoms include fatigue, vision disturbance, problems with mobility and balance and cognitive dysfunction. Many people who develop MS experience symptoms followed by a period of recovery, but over time the disease can progress to permanent disability.
The exact causes of MS are unknown. But for decades scientists have suggested a link between MS and Epstein-Barr virus (EBV). This is an infection which, when contracted in childhood, generally doesn’t cause symptoms. However, infection in adolescence can lead to glandular fever, also called the “kissing disease” or infectious mononucleosis (“mono”).
A 2022 study confirmed that people with MS have almost always been infected with EBV previously (generally the infection occurs several years before MS emerges).
But researchers are still debating exactly how this common virus could cause MS in certain people.
A bit of background
When your body encounters an infection it generates an immune response so that next time you are exposed you will already have some protection from illness.
Normally, in healthy people, immune cells called T cells and B cells are generated against a single target such as one part of a virus or bacteria, and their job is to fight infection. B cells produce antibodies which bind to and destroy invading viruses or bacteria.