What You Should Know About Epstein-Barr Virus

Chances are, you’ve been infected with Epstein-Barr virus at some point in your life. Studies suggest about 95% of adults have had it, often in their teens or early 20s. It can cause infectious mononucleosis, or mono, called “the kissing disease.” Like mono, it is easily spread through saliva and other bodily fluids.

Recent research has raised concern about Epstein-Barr virus’ potential links to multiple sclerosis and long COVID. Here’s what you should know.

What is Epstein-Barr virus?

In most cases, Epstein-Barr virus doesn’t cause symptoms. When it does, they may include fatigue, fever, inflamed throat, swollen lymph nodes in the neck, enlarged spleen, swollen liver, and rash. Because these symptoms are similar to those of other common illnesses, you may never get diagnosed with EBV. 

EBV is part of the herpes virus family, which means it remains in your body inactive, or latent, after you are infected, says Dr. Matthew Sims, director of infectious disease research at Corewell Health William Beaumont University Hospital, the new name for Beaumont Hospital, Royal Oak. “Once you're infected, that virus is always in you. But it usually doesn't come out unless something triggers it to come out. Often, that can be stress,” he says.

A blood test can determine whether you’ve been infected with EBV, but there is no vaccine. 

Recent research has linked EBV to both multiple sclerosis and long COVID, although more conclusive research is needed, doctors say. 

Multiple sclerosis

A study published in Science found an association between EBV and multiple sclerosis, a disease that affects the brain and spinal cord. The study used data from more than 10 million young adults in the U.S. military over 20 years, and it found that EBV increased the risk of developing MS.

The study found that people with EBV had 32 times the risk of developing MS, and these findings “suggest EBV as the leading cause of MS.”

Although these findings are significant, Sims says, “Right now, it's an association. Association doesn't mean causation.” He explains that EBV may be one component, but there may be something else along with it that causes MS.

Long COVID

Long COVID refers to a range of symptoms that can last weeks, months, or years after getting COVID-19. They include fatigue, respiratory and heart symptoms, and neurological symptoms.

Two recent studies have shown some correlation between EBV and long COVID. They involved much smaller groups of people than the MS study — 68 and 280 patients. The findings of both suggest that long COVID symptoms may come from latent EBV being reactivated, rather than directly from the COVID-19 virus. So COVID may trigger and reactivate EBV. 

However, these studies are limited, and bigger studies can help clarify EBV’s role in long COVID, says Dr. Teena Chopra, professor of medicine in the division of infectious diseases at the Wayne State University School of Medicine and director for hospital epidemiology at Detroit Medical Center. “There is a lot that is still unknown about long COVID.” 

“I think that the research that's going to be done on long COVID is really going to make a difference for a lot of these other conditions, potentially,” Sims says. Conditions like MS, fibromyalgia, chronic fatigue syndrome, and long COVID can be debilitating, and further research may be able to help develop diagnostic tests and treatments, Sims says.

“We also need to have an EBV vaccine, which is under way,” Chopra says. 

What can you do about it?

Because EBV is transmitted through saliva, there isn’t much you can do to avoid it. “You don't know who has it and who doesn't have it,” Chopra says. But if you avoid sharing things like drinks, food, toothbrushes, and toys, you can limit your exposure.

The bottom line: “Don't go running out and get tested for EBV. Don't freak out about it,” Sims says. “Just because you have EBV doesn't mean you're suddenly going to come down with MS later in life. Most people who have EBV don't ever have any problems.”

Further research on EBV, long COVID, and MS may help clarify the connections among them. “We need to support our researchers who are working on long COVID, our clinicians who are working nonstop and seeing patients with long COVID — we need to support them because we are going to see these patients for generations,” Chopra says. “And this is the time that we can learn more about it and we can come up with solutions.”