A mathematical model shows that a new wave of drug-resistant HIV is rising among among men in San Francisco who have sex with men and that this trend will continue over the next few years, according to a new study from the UCLA AIDS Institute. At the same time, the evolution of drug-resistant HIV may have actually reduced the severity of the city’s epidemic, saving many men from becoming infected. The model and its results were unveiled today by UCLA biomathematics professor Sally Blower, director of the Biomedical Modeling Center at the David Geffen School of Medicine at UCLA, during a session on drug-resistant diseases at the annual American Association for the Advancement of Science conference in Boston.