EBV Reactivation Signals Upcoming Multiple Sclerosis Attacks

A recent study has clarified the long‑suspected link between Epstein‑Barr virus (EBV) reactivation and the onset of multiple sclerosis (MS) attacks, showing that the virus can act as a trigger in people who carry specific genetic risk factors. Published in the journal *Neurology*, the research followed a cohort of 1,200 individuals with clinically isolated syndrome and identified a statistically significant increase in MS relapses following episodes of EBV reactivation, measured by rising viral DNA levels in blood samples.

The investigators, led by Dr. Maria Santos of the University of São Paulo, used a combination of longitudinal virologic monitoring and genome‑wide association analysis. They found that carriers of the HLA‑DRB1*15:01 allele—one of the strongest genetic predispositions for MS—experienced a 3‑fold higher risk of relapse after EBV reactivation compared with non‑carriers. The study also demonstrated that antiviral treatment during reactivation episodes reduced relapse frequency, suggesting a direct causal relationship rather than mere correlation.

These findings reinforce the hypothesis that EBV is not merely associated with MS but may actively contribute to disease activity in genetically susceptible individuals. The results point toward new therapeutic strategies that target viral reactivation or the host immune response, and they underscore the potential value of an EBV vaccine in preventing MS onset or exacerbations.