DURHAM, N.C. – An international team of researchers has identified three gene variants in the DNA of 486 people infected with HIV that appear to have helped some of the patients fight off the virus and delay the onset of full-blown AIDS. The researchers expect the new findings to aid the search for an HIV vaccine that would work by boosting the protective effects of one or more of these genes, and help the body’s own immune system overcome an infection. One of the genes looks particularly attractive as a vaccine target.