Det vides endnu ikke præcis, hvordan Extavia fungerer i forbindelse med dissemineret sklerose, men beta- interferon synes at dulme immunsystemet (kroppens naturlige forsvar) og forhindre DS- recidiver.
The exact way that Extavia works in MS is not yet known but beta-interferon seems to calm down the immune system (the body ’ s natural defences) and prevents the relapses of MS.