Dalia Rotstein, MD, MPH, St. Michael’s Hospital and The University of Toronto, Toronto, ON, shares her thoughts on the recently published evidence suggesting Epstein-Barr virus (EBV) infection may be the predominant cause of multiple sclerosis (MS) onset. A longitudinal analysis of over 10 million military personnel, published in Science in January 2022, showed that EBV seroconversion gave a 32-fold increase in the risk of MS, compared to persistent seronegativity. Dr Rotstein talks on the strengths of the evidence, which took measures to rule out confounding factors and reverse causation. The findings have generated lots of discussion in the MS community about the potential of an EBV vaccine and anti-viral therapy. This interview took place at the ACTRIMS Forum 2022 in West Palm Beach, Florida.