Multiple Sclerosis Primary Prevention, With a Focus on Epstein Barr Virus: A Narrative Literature Review for the General Practitioner
Background: Multiple Sclerosis (MS) is a potentially debilitating autoimmune demyelinating disease affecting the central nervous system (CNS) which is diagnosed between the ages of 20-49 years, leaving many years of life left for accumulation of disability (1,2). Disease modifying therapies exist to slow disease progression, but there is no curative treatment for MS (3). While the etiology of MS is incompletely understood, there are combined effects of genetics and the environment (4). Robust environmental risk factors have been identified, including vitamin D deficiency, cigarette smoking, childhood obesity, and Epstein Barr Virus (EBV) infection (4). It is estimated that up to 90.0% of MS cases are potentially preventable with risk factor modification (4). Objectives: The objective of this narrative literature review is to identify, appraise and summarize data concerning (1) the risk of MS development due to EBV infection, and (2) current progress for a prophylactic EBV vaccine. While other modifiable risk factors contribute to MS risk, recent evidence has shown that EBV infection has the most significant impact, and will therefore be the focus of this review(4,5). Methods: PubMed database was searched for relevant articles from December 14th, 2021 to January 16th, 2022. Two research questions were used; (1) ‘What is the impact of EBV infection, a modifiable risk factor, on MS incidence?’ and (2) ‘What primary prevention strategies for EBV infection are manageable in primary care?’. Studies were included for question #1 if they met the following criteria: (a) primary sources, not limited by study design, (b) available in English; (c) adult-onset MS (>16 years of age); (d) effect on incident MS cases; (e) latitudes >45° N or >45° S; and (f) in the past 5 years. Titles and abstracts were screened for relevance to the research questions before qualifying for a full article review. Results: A total of 7 articles met inclusion criteria for question (1), and a total of 9 articles for question (2). (1) EBV infection is associated with an increased risk of MS development, with the greatest risk associated with primary EBV infection in adolescence and early adulthood. (2) The majority of vaccination studies included were theoretical or in animal models. Prophylactic vaccination candidates with antigen targets for both early and latent infection appear to be promising areas for future research. There is currently no effective prophylactic EBV vaccine. Conclusion: EBV infection appears to be the most significant modifiable risk factor for MS development. While no prophylactic vaccine currently exists, the advent of such an immunization could potentially prevent up to 90% of incident MS cases. At this time, however, up to 55% of MS cases may be preventable by modification of the other significant risk factors; smoking, vitamin D insufficiency, and pediatric obesity. Though these are challenging health issues themselves, it is within the primary care provider’s scope to educate and counsel patients regarding MS primary prevention.