Enlarge ImageDesigner genes. Monkeys given a virus that holds the DNA for lab-made antibodies dodged SIV.Credit: Malcolm Linton Researchers are reporting that a new antiviral strategy powerfully protects monkeys from SIV, the simian cousin of HIV. The approach combines elements of vaccines and gene therapy, and experts say the development could eventually lead to a vaccinelike weapon against AIDS--a goal that has thus far proved elusive. Vaccines work by priming the "adaptive" immune system to recognize and attack a specific invader. But despite 2 decades of research, several potential AIDS vaccines have failed to teach the immune system to...