Exposure to siblings during early life and the risk of multiple sclerosis


  • Having siblings whose ages are close together and who are younger is associated with a reduced risk of multiple sclerosis (MS) by potentially being exposed to Epstein-Barr virus (EBV) early in life.

Why this matters

  • Accumulating evidence suggests that EBV is associated with increased risk of MS. Infectious mononucleosis (IM) is a marker for delayed EBV and is an important factor to consider in MS development.

  • Understanding the role and contribution of EBV in MS pathogenesis and the impact siblings may have on this could inform on the potential of EBV vaccines to reduce the risk of MS when administered in early life.