Using a computer model, researchers have been able to identify the unique genetic profile of people most likely to carry highly reactive sets of T cells, which makes them part an elite group of people who are naturally able to ward off HIV infections. While each individual in the group is known to carry large quantities of these T cells, anyone who can develop a new vaccine that can hunt them down and activate the T cells against HIV would be able to protect people with normal cell levels. "What we need to do with a vaccine is train bigger T-cell armies that will be there when a person first encounters the HIV virus," says Bruce Walker, director of the Ragon Institute for HIV research at Massachusetts General Hospital in Boston. Developing an effective HIV vaccine has been one of the most vexing issues in the industry, with repeated misfires. Report