Epstein-Barr virus (EBV) is linked to a surprisingly wide range of diseases, from the well-known “mono” to several cancers and autoimmune conditions. About 9 out of 10 adults carry antibodies showing a current or past EBV infection, and for most people the virus causes no ongoing problems. But in certain individuals, EBV plays a direct or contributing role in serious illnesses that can emerge years or even decades after the initial infection.
Infectious Mononucleosis
The most familiar disease caused by EBV is infectious mononucleosis, commonly called mono or “the kissing disease.” Symptoms typically appear four to six weeks after infection and include extreme fatigue, fever, sore throat, headaches, body aches, swollen lymph nodes in the neck and armpits, and a swollen liver or spleen. Some people also develop a rash.
Most people recover in two to four weeks, though fatigue can linger for several more weeks after other symptoms resolve. In some cases, symptoms persist for six months or longer. Mono is most noticeable in teenagers and young adults. Children who catch EBV earlier in life often experience mild or no symptoms at all, which is why many people never realize they’ve been infected.
Cancers Linked to EBV
After the initial infection clears, EBV doesn’t leave the body. It hides inside immune cells in a dormant state, and in rare cases this dormancy contributes to cancer. The virus is connected to several types of lymphoma and at least two epithelial cancers.
Lymphomas
Burkitt lymphoma, a fast-growing cancer most common in sub-Saharan Africa, was actually the first human cancer linked to a virus. EBV is found in the tumor cells of a substantial portion of cases, particularly the endemic form seen in African children. The virus is also present in roughly 31% of classic Hodgkin lymphoma cases, based on data from a large French case series. A subset of diffuse large B-cell lymphomas, another common type, is also EBV-associated.
These different lymphomas relate to how “active” the dormant virus is inside infected cells. In Burkitt lymphoma, the virus expresses very few of its genes, making it nearly invisible to the immune system. In other lymphomas, the virus expresses more proteins that actively drive cell growth but also make the cancer potentially more responsive to immune-based therapies.
Nasopharyngeal Carcinoma
Nasopharyngeal carcinoma is a cancer of the tissue lining the upper part of the throat behind the nose. It’s rare in most of the world but strikingly common in southern China and Southeast Asia, where rates reach up to 25 cases per 100,000 men in some cities. EBV DNA is found in virtually all nasopharyngeal carcinoma tumors, and the virus is considered a necessary factor in the disease’s development. Genetics, diet, and environmental exposures likely determine why this cancer clusters in specific populations despite EBV being ubiquitous worldwide.
Gastric Cancer
About 9% of stomach adenocarcinomas contain EBV DNA in their tumor cells. These EBV-positive stomach cancers have distinct molecular characteristics that set them apart from other gastric cancers. Given that stomach cancer is the fifth most common cancer globally, even 9% translates to a large number of cases each year.
Multiple Sclerosis
The connection between EBV and multiple sclerosis (MS) is one of the most striking findings in recent infectious disease research. A landmark study tracking over 10 million active-duty U.S. military personnel over 20 years found that EBV infection preceded MS onset in nearly every case. Of 35 individuals who were initially EBV-negative, all but one became infected with EBV before developing MS.
This doesn’t mean EBV infection guarantees MS. The vast majority of people infected with EBV never develop the disease. But the data strongly suggest that EBV infection is a prerequisite, one necessary step in a chain that also involves genetic susceptibility and possibly other environmental triggers. The mechanism likely involves the virus causing the immune system to mistakenly attack the protective coating around nerve fibers in the brain and spinal cord.
Lupus and Other Autoimmune Diseases
Essentially everyone with systemic lupus erythematosus (lupus) is infected with EBV, and recent research from Stanford Medicine has clarified why. The virus can convert the immune cells it infects into what researchers describe as “diabolical overlords” that reprogram other immune cells to attack the body’s own tissues. Specifically, EBV-infected B cells (the immune cells that produce antibodies) begin activating other B cells to produce antibodies against the body’s own proteins and DNA, driving the widespread tissue damage seen in lupus.
The Stanford team believes this applies to 100% of lupus cases, though they suspect only certain EBV strains trigger this transformation. The same researchers note hints that a similar EBV-driven cascade may play a role in rheumatoid arthritis and Crohn’s disease, though the evidence for those conditions is still being developed.
Chronic Active EBV Disease
In rare cases, the body fails to bring EBV under control after the initial infection. Chronic active Epstein-Barr virus disease (CAEBV) is diagnosed when mono-like symptoms persist for more than three months, EBV levels in the blood remain elevated, and the virus can be detected in affected tissues. Unlike ordinary mono, CAEBV involves the virus infecting blood-forming stem cells, which disrupts both the innate and adaptive immune systems and causes ongoing inflammatory symptoms.
CAEBV is a serious condition that can damage multiple organs over time. It’s distinct from the lingering fatigue some people experience after mono, which resolves on its own. CAEBV requires specialized treatment and monitoring.
Why One Virus Causes So Many Diseases
The reason a single virus is tied to such diverse conditions comes down to how EBV behaves after infection. Unlike a cold virus that your body clears completely, EBV establishes a lifelong residence inside B cells. It cycles through different dormancy programs, sometimes expressing just a single viral protein, sometimes expressing a full panel of genes that push cells to grow and divide. Which dormancy program is active, combined with a person’s genetics and immune health, determines whether the virus stays quietly controlled or contributes to disease.
People with weakened immune systems, whether from organ transplantation, HIV, or genetic immune deficiencies, face a higher risk of EBV-related cancers because their bodies are less able to keep the dormant virus in check.
Vaccines and Prevention
There is currently no approved vaccine against EBV, but development is underway. Moderna has a candidate vaccine called mRNA-1189 in Phase 1/2 clinical trials, targeting healthy adolescents and adults ages 10 to 30. The trial uses the same mRNA technology behind COVID-19 vaccines. If successful, an EBV vaccine could potentially prevent not just mono but also reduce the long-term risk of EBV-associated cancers and autoimmune diseases, making it one of the more consequential vaccines in development today.