Experimental Therapies in Multiple Sclerosis: Epstein–Barr Virus and Potential EBV-Related Therapeutic Strategies—A Systematic Review

Background/Objectives: Multiple sclerosis (MS) constitutes a chronic autoimmune, inflammatory, and neurodegenerative disease, with dissemination in space and time, warranting diagnosis. Epstein–Barr virus (EBV) is increasingly recognized as a key contributor to MS pathogenesis. This review summarizes evidence on EBV-related mechanisms of currently approved disease-modifying therapies (DMTs) and emerging EBV-directed therapeutic strategies in MS. Methods: A systematic search of PubMed, Embase, Cochrane, and Web of Science was performed. Original English-language studies addressing EBV-related therapeutic mechanisms or EBV-targeted interventions in MS were included; 23 studies met the inclusion criteria. Results: Current DMTs may influence EBV-related immunity through diverse mechanisms, including modulation of B-cell subsets, altered lymphocyte trafficking, reduction in EBV-specific humoral responses, and restoration of T-cell surveillance. Monoclonal antibody-based therapies, particularly anti-CD20 agents and natalizumab, appear to affect the EBV–B-cell–immune axis through distinct but complementary mechanisms. Other interventions, including interferons, glatiramer acetate, dimethyl fumarate, autologous hematopoietic stem cell transplantation, and vitamin D supplementation, may also modulate EBV-specific cellular or humoral responses, although the magnitude and durability of these effects vary. Emerging EBV-directed approaches, including EBV-specific T-cell therapy, inhibition of specific proteins, modulation of autophagy, and cholesterol-dependent viral latency, provide additional support for targeting EBV-related pathways in MS. Conclusions: The therapeutic efficacy of DMTs in MS may extend beyond nonspecific immunomodulation and involve partial disruption of EBV-driven immune persistence. Further controlled studies are required to validate EBV-related biomarkers and determine whether direct EBV-targeted therapies can provide sustained clinical benefit.