A new study from the Karolinska Institute strengthens evidence that Epstein–Barr virus (EBV), the common cause of glandular fever, can trigger an immune response that damages the brain and may contribute to the development of multiple sclerosis (MS). The research supports the hypothesis that EBV infection is a key environmental driver of MS, a chronic inflammatory neurological disease affecting nearly three million people worldwide, in which the immune system attacks the central nervous system.