Science magazine reviews the disappointing results of two recent HIV vaccine clinical trials, which “sugges[t] that a successful vaccine, the most effective way to slow if not end the epidemic, lies far in the future.” The news service focuses on the experimental vaccines’ use of adenovirus vectors, which “are widely used in experimental vaccines and gene therapy studies” and show some evidence of increasing the risk of HIV infection. “Other than a large-scale trial of a new and improved version of RV144 set to start in South Africa in 2015, all HIV trials currently in the works are at very early stages,” Science notes (Cohen, 5/10).