San Antonio scientists are gearing up to put a lab-made monoclonal antibody called mAb 77 to the test in juvenile rhesus monkeys as early as next month, a key step toward what could become the first targeted treatment for measles. The timing is no accident, coming as measles cases climb again in the United States and worldwide after years of slipping vaccination coverage, with public health officials especially worried about severe illness in young children.
Viraj Kulkarni, a principal investigator at Texas Biomed, told San Antonio Report that the institute plans to launch safety and efficacy studies of mAb 77 in its juvenile rhesus population next month. "If successful, this is going to at least be an option for kids," Kulkarni said, noting the team is particularly concerned about those under 5. The upcoming primate work builds on collaborations with researchers who first characterized the antibody in laboratory and rodent studies.
How mAb 77 Could Work
Researchers detailed mAb 77 in a 2024 paper that used structural and cell-based experiments to show the antibody can neutralize measles by latching onto parts of the virus’s fusion machinery and blocking its entry into cells, as reported in Science. The project, led by teams at the La Jolla Institute for Immunology and Columbia University, found strong neutralizing activity in both cell and rodent models and suggested that mAb 77 could potentially serve as a preventive tool as well as a treatment, according to the La Jolla Institute for Immunology.
Why A Treatment Matters
There is still no specific FDA-approved antiviral drug for measles; current care relies on supportive treatment such as fluids, fever control and antibiotics for secondary infections, along with vitamin A for children in some settings, according to the Centers for Disease Control and Prevention. Despite the existence of an effective vaccine, measles was estimated to have killed roughly 95,000 people in 2024, mostly in regions with low vaccine coverage, a global burden that underscores the need for more tools to fight the virus, per the WHO.
Outbreaks And Vaccine Gaps
The new testing plans arrive as measles makes an unwelcome comeback in the United States following declines in childhood vaccination rates, with some experts warning that continued transmission could jeopardize the country’s elimination status. Texas has already seen cases and potential exposures in recent outbreaks, according to the Texas Department of State Health Services, while national coverage has highlighted the broader threat to U.S. measles control in recent months, as analysts have pointed out in Live Science.
Kulkarni stressed that a monoclonal antibody would be a safety net, not a replacement for routine shots, and urged families to keep up with vaccination as the first line of defense. "It’s a big problem, and we have a simple solution for it," he told the San Antonio Report, adding that if the primate studies confirm mAb 77’s performance, the candidate could move into early human clinical trials.
