Most adults carry Epstein–Barr virus (EBV), often without ever knowing it. The infection usually causes few symptoms and then remains in the body for life. For the vast majority of people, it never leads to serious illness.
But growing research suggests this very common virus may play a role in an autoimmune disease called multiple sclerosis (MS), a long‑term disease that affects the brain and spinal cord. Previous study also showed EBV is linked to Lupus, another autoimmune disease.
New findings are beginning to explain how EBV could help set the disease in motion, offering clues that may shape future treatments and prevention strategies.
Why EBV has become a focus in MS research
MS occurs when the immune system mistakenly attacks the central nervous system. This damages myelin, the protective coating around nerve fibres that allows electrical signals to travel quickly. When myelin is lost, messages between the brain and body slow down or fail, causing symptoms such as vision problems, difficulty walking, poor balance and persistent fatigue.
MS often begins in early adulthood and affects millions of people worldwide. While genetics and environmental factors are known to influence risk, EBV has emerged as one of the strongest and most consistent links identified so far.
What the new research found
In recent work, a research team has explored how EBV infection might contribute to the earliest stages of MS. They used laboratory mice engineered to have a human‑like immune system, allowing them to study immune behaviour in detail.
After EBV infection, certain immune cells became unusually active and entered the brain, where they triggered inflammation and early tissue damage.
Specifically, B cells — immune cells that produce antibodies and help coordinate immune responses — behaved abnormally after infection. These EBV‑affected B cells travelled into the brain and released chemical signals that attracted T cells, another type of immune cell responsible for killing infected or abnormal cells.
Together, these cells caused inflammation and early brain damage similar to what researchers believe occurs at the beginning of MS. When they used a commonly prescribed medicine to remove B cells, far fewer T cells entered the brain and overall immune activation dropped sharply.
In effect, EBV appears to change how B cells behave, turning them into drivers of inflammation that draw other immune cells into the brain, where damage can occur.
How this fits with evidence from people with MS
These findings match observations from human studies. Researchers have found unusually high numbers of EBV‑targeting immune cells in the cerebrospinal fluid that surrounds the brain and spinal cord of people with MS. Many of these cells are T cells primed to recognise the virus.
This suggests the immune system may be responding to EBV activity within the central nervous system itself. When immune cells gather there, they can spark inflammation, allowing even more immune cells to enter and cause local damage.
Over time, this leads to the formation of lesions that underpin many MS symptoms.
Why most people with EBV do not develop MS
Given how common EBV infection is, a key question remains: why doesn’t everyone develop MS?
The answer appears to lie in a combination of risk factors. Genetics, sex, smoking, obesity and low vitamin D levels all influence MS risk. EBV seems to be an important contributor, but it is unlikely to act alone.
EBV infects B cells and can remain dormant inside them for life. In some circumstances, the virus may reactivate or alter how these cells function.
One leading explanation is a form of mistaken identity, where immune responses originally aimed at EBV begin to resemble attacks on myelin, causing the immune system to damage nervous tissue by mistake.
What this means for current treatments
Most existing MS treatments work by calming the immune system rather than targeting a single cause. Many are immunosuppressive, which can reduce relapses and slow disease progression but also increase the risk of infections.
Some of the most effective therapies specifically target B cells using monoclonal antibody drugs such as ocrelizumab, rituximab and ofatumumab. These medicines reduce B cell numbers and may also lower the pool of EBV‑infected cells.
This may help explain why these treatments are so effective. However, because they suppress part of the immune system, they require careful monitoring to balance benefits against risks, including reduced responses to infections and vaccines.
Could preventing EBV prevent MS?
An obvious question is whether stopping EBV infection could prevent MS from developing in the first place.
Developing an EBV vaccine has proved challenging because the virus hides inside cells and establishes lifelong infection. Several vaccines and immune‑based approaches are under investigation, but none are currently approved. It also remains unclear whether preventing EBV infection alone would be enough to substantially reduce MS risk.
For now, this research does not change medical advice for the general public. Instead, it helps scientists refine where to focus future prevention and treatment efforts.
What comes next
The link between EBV and MS is now one of the most active areas of MS research. Rather than viewing MS solely as an immune disorder, researchers are increasingly exploring whether targeting EBV‑infected B cells could prevent disease development or slow its progression.
Understanding and controlling how this common virus shapes immune behaviour may be key to explaining why MS begins — and, eventually, to stopping it before lasting damage occurs
The post How a Common Lifelong Virus May Help Trigger Multiple Sclerosis, an Autoimmune Disease first appeared on PP Health Malaysia.
