Monoclonal Antibody Advances Target Measles, Lyme Disease, and Epstein-Barr Virus

Researchers are advancing monoclonal antibody therapies against measles, Lyme disease, and Epstein-Barr virus (EBV), with recent studies reporting progress in each area. In a Phase I clinical trial, an investigational antibody for Lyme disease was well tolerated and maintained protective blood levels for at least four months, while preclinical studies yielded antibodies that block EBV infection and the measles virus.

A Phase I clinical trial of TNX-4800, a human monoclonal antibody for the prevention of Lyme disease, was well tolerated and showed lasting serum concentrations in participants, according to data presented at the World Vaccine Congress 2026 in Washington D.C. TNX-4800, formerly mAb 2217LS, is licensed to Tonix Pharmaceuticals. The trial enrolled 44 healthy subjects aged 19 to 65, with 41 completing it; results showed no significant clinical or laboratory safety signals, with most adverse events mild or moderate. Potentially protective blood levels were seen at two days and sustained for at least four months due to the antibody's extended half-life design. TNX-4800 blocks the maturation of Borrelia burgdorferi in the mid-gut of infected deer ticks, inactivating the bacteria before it reaches the skin. An adaptive Phase 2 field study is expected to begin in the first half of 2027, pending FDA clearance. The chief executive officer of Tonix Pharmaceuticals said the antibody is expected to provide a preventative option for the 87 million people in the United States at high risk of contracting Lyme disease. He also noted that Lyme disease vaccines in development that elicit antibodies to OspA take more than six months to offer protection and require complex immunization schedules. According to the Centers for Disease Control and Prevention, there are more than 450,000 cases of Lyme disease annually in the U.S.

Scientists at Fred Hutch Cancer Center have developed genetically human monoclonal antibodies that prevent two key EBV antigens, gp350 and gp42, from binding to and entering human immune cells. The study, published in Cell Reports Medicine, used mice with human antibody genes and yielded two antibodies against gp350 and eight against gp42. One antibody against gp42 successfully prevented infection in mice with human immune systems challenged with EBV; another against gp350 provided partial protection. EBV, which infects an estimated 95% of the global population, is linked to multiple types of cancer and other chronic conditions. More than 128,000 people in the U.S. undergo solid organ and bone marrow transplant annually, and there are no specific therapies to prevent EBV infection or reactivation in immunosuppressed patients. Post-transplant lymphoproliferative disorders (PTLD), most of which are EBV-associated lymphomas, are a frequent cause of morbidity and mortality after organ transplantation. The scientists envision a future therapy in which an infusion of these monoclonal antibodies could prevent PTLD. Fred Hutch has filed for intellectual property rights covering the antibodies, and researchers are working with collaborators and an industry partner to advance a potential therapy.

Using blood from a 56-year-old woman vaccinated against measles, scientists have isolated four potent virus-blocking antibodies that could pave the way toward a treatment for people exposed to measles. The study, published in Cell Host & Microbe, identified antibodies that target the H protein, which allows the virus to latch onto cells, and the F protein, which helps it fuse to cells. Two antibodies lock the F protein into one shape, and two bind to the H protein. In rodents, the antibodies knocked down the amount of virus in their lungs when given one to two days after infection. The approach is not a substitute for vaccination; a safe, highly effective measles vaccine has been available since the 1960s, and the U.S. officially eliminated the disease in 2000, but dropping vaccination rates have sparked large outbreaks. New ways to block or treat measles are particularly important for immunocompromised people and babies under age 1, who are not eligible for the vaccine.

The president of the La Jolla Institute for Immunology, who led the measles study, said the treatment would always be more expensive than the vaccine and is meant for people who could not be vaccinated. A pediatrician at Children's Hospital of Philadelphia noted that the approach would probably have to be given shortly after exposure to be effective, long before symptoms develop, and that immune globulin is already a possible treatment.