Epstein–Barr virus

Lore & Background

The Epstein–Barr virus infects B cells of the immune system and epithelial cells. In rare pathological contexts, it may also infect T cells and NK cells. Infection occurs primarily by oral transfer of saliva. Most people become infected and gain adaptive immunity; in the United States, about half of all five-year-old children and about 90% of adults have evidence of previous infection. Infants become susceptible as soon as maternal antibody protection disappears. Most children who become infected display no symptoms, or symptoms indistinguishable from other mild illnesses. When infection occurs during adolescence or young adulthood, it causes infectious mononucleosis 35 to 50% of the time.

Reader's Guide

The Epstein–Barr virus is significant as the first identified oncogenic virus, with about 200,000 cancer cases globally per year attributable to it. It is the most common cause of infectious mononucleosis and is tightly linked to malignant diseases such as Burkitt lymphoma, Hodgkin's lymphoma, gastric cancer, and nasopharyngeal carcinoma, as well as autoimmune diseases like systemic lupus erythematosus and rheumatoid arthritis. A large study following 10 million active US military over 20 years suggested EBV as the leading cause of multiple sclerosis, with a recent infection causing a 32-fold increase in risk. Despite various vaccine formulations tested in humans and other animals, none have been able to prevent EBV infection, and no vaccine has been approved to date. The virus establishes lifelong latency in memory B cells, with three distinct latency programs. Its legacy includes ongoing research into its role in cancer and autoimmune diseases, and the challenge of developing an effective vaccine.

Did You Know?

• About 200,000 cancer cases globally per year are thought to be attributable to EBV.
• No vaccine has been approved to date to prevent EBV infection.