A group of Australian researchers at the Universities of Melbourne and New South Wales have developed new tools and paradigms to understand immune evasion from HIV. The study, published Friday, January 25 in PLoS Pathogens, shows that both prior vaccination and timing influence the rates of immune escape, providing further insight into the effectiveness of T cell immunity to HIV.

Merck & Co., Inc. and the HIV Vaccine Trials Network (HVTN) today announced that study volunteers in the STEP study of Merck's HIV vaccine (V520) will be told whether they received vaccine or placebo, and all study volunteers will be encouraged to continue to return to their study sites on a regular basis for ongoing risk reduction counseling and study-related tests.