Brain intertwined with herpesvirus vine, symbolizing connection to neurological impact.

Decoding MS: Can a Common Virus Be the Missing Piece?

Mira Elwood in Health & Wellness August 2025 • 4 min read.

"New research unveils how herpesviruses might trigger multiple sclerosis, paving the way for future prevention strategies."

Multiple sclerosis (MS), a debilitating autoimmune disease, has long puzzled scientists. While genetic predisposition plays a role, environmental factors, particularly viral infections, are increasingly suspected as triggers. Among these, human herpesviruses (HHVs), such as Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6), have emerged as prime suspects.

However, the challenge lies in the timing. HHV infections are incredibly common, often occurring in early childhood, while MS typically manifests in adulthood. This time gap makes it difficult to establish a direct causal link. Now, a new study using nonhuman primates offers compelling evidence of how HHV-6 might accelerate the development of an MS-like disease.

This article delves into the groundbreaking research that demonstrates how asymptomatic HHV-6 infection can act as a trigger, accelerating neuroinflammation and mimicking the progression of MS in a nonhuman primate model. We'll explore the study's findings, their implications for understanding MS, and the potential for future preventative strategies.

The Herpesvirus-MS Connection: What the Study Revealed

Brain intertwined with herpesvirus vine, symbolizing connection to neurological impact.

Researchers at the National Institutes of Health investigated the impact of HHV-6 on experimental autoimmune encephalomyelitis (EAE), an animal model for MS, using common marmosets. Marmosets are susceptible to HHV-6 infection and exhibit EAE with similarities to MS in humans, making them an ideal model.

The study involved intranasally inoculating marmosets with HHV-6A, HHV-6B, or a control substance. Intranasal inoculation mimics the natural route of HHV-6 infection in humans. Key findings included:

Asymptomatic Infection: Marmosets inoculated with HHV-6 remained asymptomatic, mirroring the typical course of early HHV-6 infection in humans.
Accelerated EAE: Despite the lack of symptoms, HHV-6-infected marmosets experienced a significantly faster onset and more severe progression of EAE compared to control animals.
Immune Response: An expansion of a pro-inflammatory CD8 T cell subset correlated with survival rates in the virus/EAE marmosets, hinting at a possible viral antigen-driven immune response.
Viral Antigen Localization: HHV-6 viral antigen was markedly elevated and concentrated within brain lesions of virus/EAE marmosets, similar to what has been observed in MS brain lesions.

These findings suggest that even an asymptomatic HHV-6 infection can prime the immune system, making individuals more susceptible to developing MS later in life. The study also highlights the importance of considering viral infections as potential environmental triggers for autoimmune diseases.

Implications and Future Directions: What This Means for MS

This research provides compelling evidence for the role of HHV-6 as a potential trigger for MS. It suggests that early exposure to the virus, even without causing noticeable symptoms, can alter the immune system and increase the risk of developing the disease later on.

The study's findings open new avenues for MS prevention and treatment. Future research could focus on:

<ul> <li>Antiviral Therapies: Investigating whether antiviral medications can prevent or delay the onset of MS in individuals with HHV-6 infection.</li> <li>Vaccine Development: Developing a vaccine against HHV-6 to reduce the risk of infection and subsequent MS development.</li> <li>Immune Modulation: Exploring strategies to modulate the immune system in individuals with HHV-6 infection to prevent the development of autoimmunity.</li> </ul> By further exploring the link between herpesviruses and MS, we can pave the way for innovative strategies to prevent and treat this debilitating disease, offering hope for millions affected worldwide.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1073/pnas.1811974115, Alternate LINK

Title: Herpesvirus Trigger Accelerates Neuroinflammation In A Nonhuman Primate Model Of Multiple Sclerosis

Subject: Multidisciplinary

Journal: Proceedings of the National Academy of Sciences

Publisher: Proceedings of the National Academy of Sciences

Authors: Emily C. Leibovitch, Breanna Caruso, Seung Kwon Ha, Matthew K. Schindler, Nathanael J. Lee, Nicholas J. Luciano, Bridgette J. Billioux, Joseph R. Guy, Cecil Yen, Pascal Sati, Afonso C. Silva, Daniel S. Reich, Steven Jacobson

Published: 2018-10-15

Everything You Need To Know

What is multiple sclerosis (MS), and why is it important to this research?

Multiple sclerosis (MS) is a chronic autoimmune disease where the immune system attacks the protective covering of nerve fibers in the brain and spinal cord. This leads to a wide range of neurological symptoms, including vision problems, muscle weakness, and difficulties with coordination. In the context of the research, understanding MS is crucial because the study investigates potential triggers, like human herpesviruses (HHVs), for its development. The implications are significant, as they could lead to new preventative strategies and treatments.

What are human herpesviruses (HHVs), and how are they connected to the development of multiple sclerosis (MS)?

Human herpesviruses (HHVs), particularly Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6), are being investigated as potential triggers for multiple sclerosis (MS). These viruses are incredibly common, with infections often occurring in early childhood. The research suggests that even asymptomatic HHV-6 infections can prime the immune system, making individuals more susceptible to developing MS later in life. This is a significant link because it suggests that early exposure to the virus, even without causing noticeable symptoms, can alter the immune system and increase the risk of developing the disease.

What is experimental autoimmune encephalomyelitis (EAE), and why was it used in this study?

Experimental autoimmune encephalomyelitis (EAE) is an animal model used to study multiple sclerosis (MS). Researchers use EAE to understand the mechanisms behind MS and test potential treatments. In this study, researchers used common marmosets, which are susceptible to both human herpesvirus 6 (HHV-6) infection and EAE. The study's findings using the marmoset model showed that asymptomatic HHV-6 infection significantly accelerated the onset and severity of EAE, providing valuable insights into how HHV-6 might contribute to the development of MS in humans. This model is important for studying the disease and testing potential treatments.

What were the main findings of the study about HHV-6 and MS?

The study's key findings include the link between asymptomatic HHV-6 infection and accelerated experimental autoimmune encephalomyelitis (EAE) progression, the expansion of a pro-inflammatory CD8 T cell subset, and the elevated presence of HHV-6 viral antigen within brain lesions. These suggest that early exposure to the virus, even without causing noticeable symptoms, can alter the immune system and increase the risk of developing multiple sclerosis (MS). This suggests the importance of considering viral infections as potential environmental triggers for autoimmune diseases. The presence of the viral antigen within the brain lesions in marmosets further supports this connection, mirroring what is observed in MS brain lesions.

What are the implications of the study's findings for the future of multiple sclerosis (MS) research and treatment?

This research suggests that human herpesvirus 6 (HHV-6) may act as a trigger for multiple sclerosis (MS). It indicates that even an asymptomatic infection can prime the immune system, increasing the risk of developing MS later. The study's findings provide compelling evidence for considering viral infections as potential environmental triggers for autoimmune diseases. This understanding could revolutionize how we approach MS, potentially leading to the development of preventive strategies. For instance, understanding this connection might allow for the early detection of those at risk, or it could lead to the development of vaccines or antiviral treatments.