The time to prioritise MS prevention is now
Multiple sclerosis (MS) remains a significant global health challenge, affecting more than three million people worldwide.
With treatments steadily improving and key risk factors now better understood, the path toward preventing MS is clearer than ever. Only a small fraction (6%) of global MS research funding has been devoted to prevention.
But landmark discoveries in MS and successes in delaying or preventing other immune diseases provide new hope that MS prevention is now a realistic goal.
In April 2025, a Global Prevention Workshop sponsored by MS Canada and MS Australia brought together around 60 diverse experts in Lisbon, Portugal, to discuss current knowledge and priorities for MS prevention.
The recommendations from the workshop, published this week in MS Journal, set the stage for a global prevention agenda for MS.
Dr. Pamela Valentine, President and CEO of MS Canada, is resolute in her pursuit of the transformative possibilities that lie ahead. “Our goal is ambitious but key discoveries, new technology and momentum in the field give us an unprecedented opportunity. This initiative will advance our understanding of risk, help diagnose MS earlier and intervene sooner. The time to take on MS prevention is now,” Dr. Valentine said.
Developing a framework for MS prevention
To help frame the targets for MS prevention, experts mapped how MS evolves. The biological processes leading to MS begin many years before the onset of symptoms. There are genetic risk factors, environmental triggers that interact with these genes, and ultimately, the clinical onset of MS when symptoms appear. If we can understand these processes better, there is potential for earlier detection, and finding new ways to prevent, slow or stop MS.
Potential interventions to prevent MS can be grouped according to timing.
- Primordial prevention refers to preventing MS risk factors, such as obesity or infectious mononucleosis, before they occur.
- Primary prevention involves targeting existing risk factors, such as low vitamin D, to prevent disease.
- Secondary prevention involves detecting MS in its earliest stages to delay or prevent progression and stopping MS from getting to the ‘next worse stage’.
Primordial and Primary Prevention: addressing risk factors
Towards an agenda for primordial and primary prevention, the workshop considered several important questions. Who to prioritise? Which MS risk factors should be addressed first? Is timing important? What are the most effective interventions?
The genetic risk of MS includes over 230 genes that are also common in people without MS. While genetics can’t be altered, they might help us identify people at the highest risk for closer monitoring, and to understand the earliest stages of MS. Most of the current evidence comes from white European populations, so more research is needed.
Environmental risk factors include the Epstein-Barr virus (EBV), childhood/adolescent obesity, low sunlight exposure, low vitamin D and cigarette smoking. Recent landmark research suggests EBV infection is necessary for the development of MS and may offer the most potential for MS prevention, using vaccines or even anti-viral drugs.
What’s Next?
There is great potential to reduce the risk of MS, because many risk factors involve lifestyle or infection that could be targeted. A multi-pronged approach addressing multiple risk factors was recommended. The workshop emphasised acting on current knowledge, targeting factors that can be modified, building coalitions, and making the economic case for prevention.
Secondary Prevention starts with very early detection
Many of the same questions exist for secondary prevention of MS: when, how, and in whom to intervene to delay or prevent MS?
Many years before the clinical onset of MS, there is a “biological onset” of disease processes. In some people, a “prodromal” phase occurs, with non-specific symptoms such as headache, and increased use of healthcare.
At present, it is very difficult to detect the stage prior to symptom onset or the MS prodrome in real time. However, there are promising markers in the blood, such as markers of nerve damage, and antibodies against brain proteins or EBV. These might help in the very early detection of MS and provide a window to stop MS before it starts.
What’s Next?
The workshop recommended continued work to find and validate markers for early detection of MS, especially tests for changes in the immune system.
Further work is needed to link these markers to long-term outcomes. This will require collaboration to design long-term studies that address knowledge gaps and build high-risk cohorts for future intervention studies.
The tools for early detection will need to be accessible and affordable globally. These will be critical in designing feasible clinical trials to delay or prevent MS in the future.
Intervention Strategies to prevent MS
The role and potential effectiveness of different types of interventions were discussed. Interventions targeting the whole population would have a broader reach but lower intensity. These would include inventions to reduce smoking or obesity.
Interventions in individuals are more intensive but can be more targeted and more effective for the person. These could include short-term or one-off protective treatments such as EBV vaccines, longer-term therapies such as vitamin D or immune therapies, or support to enact lifestyle changes.
Successes in other autoimmune diseases, such as type 1 diabetes, provide great hope. Intensive research efforts over many years have identified blood markers that allow very early detection of disease. This has enabled clinical trials of very early immune therapies that have successfully delayed the onset of disease, and there are more trials underway.
What’s Next?
Effective MS prevention will require interventions at multiple levels, tailored to local contexts and life stages.
There are important ethical considerations. What if someone is found to be at higher risk of MS, but there is nothing available yet to halt or prevent it? What if there are potential early treatments, but they carry a risk? How do people living with MS feel about preventative interventions for their children, if they become available? Ethical principles will be developed to guide researchers who are identifying high-risk individuals or those with very early MS.
Interventions in those who are yet to develop MS – and as such are currently well – require thoughtful communication of risks and benefits.
To implement MS prevention interventions globally, building capacity in low-resource regions and prioritising affordable, scalable interventions must be considered.
What else do we need to make prevention a reality?
Measurements of Success
Essential to the Global Prevention Initiative is evaluating the success of future prevention strategies. Measuring engagement and uptake of interventions is key, and assessing the impact beyond just reducing new MS cases. For example, the workshop identified reduced school/work absences and economic evaluations, such as lower healthcare costs, as potential measurable outcomes.
Coalitions across sections and stakeholders
Building coalitions across sectors will be critical for MS prevention. Coalitions can pool resources, build awareness, help communicate the message, and advocate for policy changes.
Different stakeholders bring diverse perspectives, and their inclusion will be essential in developing the interventions that result in change. The stakeholders include people with MS, those at risk of developing MS, MS organizations, and groups targeting the same risk factors for other conditions. Another key stakeholder is the public health agencies, with their broad focus on disease prevention at a population level.
A wide-ranging communication plan will be vital. The workshop considered communication of existing risk factors, as well as ways to communicate strategies for early detection and intervention across the stakeholder groups.
Future Directions
Our understanding of MS disease processes has advanced, but we will need long-term and well-coordinated global efforts to prevent MS.
Prioritizing and funding key areas, building international coalitions, and working with other global initiatives, such as the global Pathways to Cures Initiative, will be essential to achieving this goal.
