Scientists Discover an Antibody That Protected Mice From Epstein-Barr Virus Infection

The Epstein-Barr virus, known as EBV, is one of the most widespread human pathogens, infecting an estimated 90–95% of adults worldwide. Once it enters the body, it can remain dormant for decades and reactivate later in life, often without obvious symptoms.

EBV is best known as a cause of infectious mononucleosis, sometimes called the kissing disease. However, it is also linked to several cancers, including Hodgkin lymphoma and nasopharyngeal carcinoma, and has been strongly associated with multiple sclerosis in recent large studies.

For people with a healthy immune system, EBV infection is usually mild or may go unnoticed entirely. By contrast, individuals with weakened immunity, including patients who have received organ or stem cell transplants, face a much greater risk of serious EBV-related complications.

How the antibody was discovered

The new research focused on two key proteins on the surface of the virus, gp350 and gp42. These proteins help EBV bind to and enter B lymphocytes, the immune cells the virus uses as a long-term reservoir in the body.

Blocking these entry points could prevent EBV from infecting B cells in the first place and may also limit reactivation later in life. This approach is particularly attractive because EBV establishes a lifelong infection that current treatments cannot eliminate.

To identify highly specific antibodies, scientists used genetically engineered mice carrying human genes responsible for antibody production. The animals were exposed to selected EBV proteins to trigger an immune response similar to that seen in humans.

The approach produced 10 previously unknown antibodies targeting the virus. Two recognized the gp350 protein, while the remaining eight targeted gp42. Researchers then tested how effectively each antibody could interfere with EBV infection in subsequent experiments.

One gp42-directed antibody emerged as particularly promising. In preclinical experiments, it protected modified mice from EBV infection, suggesting that it could block a critical step in the virus’s entry into immune cells and prevent infection from becoming established.

Why Epstein-Barr is so challenging

Developing treatments against EBV has long been difficult because the virus is finely adapted to interact with B cells. It can remain hidden inside these cells in a latent state, making it difficult for both the immune system and medications to completely eliminate the infection.

Natural antibodies produced during common EBV infections do not always provide strong, lasting protection against reinfection or reactivation. This has limited their usefulness as a direct foundation for targeted therapies or preventive treatments.

The new study attempts to overcome this limitation by deliberately directing the immune response toward vulnerable parts of the virus. By creating conditions that favored antibodies against gp42 and gp350, researchers isolated candidates capable of directly interfering with critical viral functions.

Experts say this targeted approach could help guide the development of future monoclonal antibody therapies and potentially provide a template for vaccines or combination treatments against EBV and related members of the herpesvirus family.

Potential for transplant patients and beyond

The potential therapeutic value of the new antibody may be particularly important in transplant medicine. People receiving organ or stem cell transplants must take immunosuppressive medications to reduce the risk of rejection, weakening their natural defenses against viruses such as EBV.

In this vulnerable population, EBV can trigger post-transplant lymphoproliferative disorder, a condition in which B cells multiply uncontrollably. This can lead to aggressive lymphomas that are difficult to treat and may be life-threatening despite modern therapies.

A safe and effective EBV-neutralizing antibody could potentially protect high-risk patients during periods of intense immunosuppression. It might be administered preventively or used as part of early intervention when blood tests detect rising EBV levels.

Beyond transplantation, an antibody-based strategy could eventually be investigated in people with other immune disorders or those at elevated risk of EBV-related cancers. Researchers also see potential in examining whether such antibodies could reduce the risk of conditions suspected to be linked to EBV, including multiple sclerosis.

Next steps and broader implications

Despite the encouraging findings, the antibody remains far from routine clinical use. All current evidence comes from preclinical animal models, which are essential for early research but cannot fully predict how a therapy will behave in humans.

Before it can reach patients, the antibody will require extensive safety testing, including toxicity studies and research to determine appropriate doses. It could then progress to carefully controlled clinical trials evaluating its safety and effectiveness in people.

The scientists behind the work emphasize that one of the most important achievements may be the method itself. The platform used to generate and select anti-EBV antibodies could potentially be adapted to target other viruses that depend on specific proteins to enter cells.

As researchers increasingly recognize the long-term consequences of persistent viral infections, targeted antibodies are attracting attention as potential tools for both prevention and treatment. For EBV, which silently infects most of humanity and remains in the body for life, the potential implications are particularly significant.

The findings, published in Cell Reports Medicine, add to global efforts to bring targeted EBV therapies and vaccines closer to reality. If successful, these approaches could eventually change the outlook for patients at risk of serious EBV-related diseases.