Clinical tests began today of a novel vaccine directed at the three most globally important HIV subtypes, or clades. Developed by scientists at the Dale and Betty Bumpers Vaccine Research Center, part of the National Institute of Allergy and Infectious Diseases, the vaccine incorporates HIV genetic material from clades A, B and C, which cause about 90 percent of all HIV infections around the world. “This is the first multigene, multiclade HIV vaccine to enter human trials,” said NIAID Director Anthony S. Fauci, M.D. “It marks an important milestone in our search for a single vaccine that targets U.S. subtypes of HIV as well as clades causing the global epidemic.”