Multiple Sclerosis, Viruses, and New Vaccines

In certain circumstances, for example, when the immune control of EBV is disrupted by induced immune suppression, a very severe disease—post transplant lymphoproliferative disorder [11]—can result. There is an increasing likelihood that EBV vaccines may become available, raising the possibility of prophylactic vaccination to prevent MS. There is emerging evidence that infection by another human herpesvirus—cytomegalovirus (CMV)—may be negatively associated with the development of MS. Several studies [17,18,19] have reported significantly lower seroprevalences of CMV IgG in people with MS compared to non-MS controls. Furthermore, congenital CMV infection can lead to abnormal foetal development and is a leading cause of sensorineural hearing loss. For these reasons, CMV vaccines are under active development [21,22] raising the possibility of a potential application for the prevention of MS. The responses of people with multiple sclerosis to routine vaccinations have been a topic of considerable interest given the use of disease-modifying therapies (e.g., anti-CD20) that directly impact the host’s immune response [23,24].