By Miriam Falco CNN Medical Producer (CNN) – A vaccine to prevent HIV infection has shown modest results for the first time, researchers have found. [cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/HEALTH/09/24/hiv.vaccine/art.vaccine.gi.jpg caption="Researchers found those who received the vaccine combination were 31 percent less likely to contract HIV."] In what is being called the world's largest HIV vaccine trial … Continue reading HIV vaccine is possible, researchers say