In a small study, researchers found that the experimental drug — called pritelivir — substantially curbed "viral shedding" in people with genital herpes. That means it decreased the amount of time the virus was active and potentially transmissible to patients' sexual partners. There is still a lot of research to be done, said Dr. Richard Whitley, an infectious disease expert at the University of Alabama at Birmingham, who wrote an editorial published with the study. But he said it's good news that drugs that work in new ways are under development.