The human trials came from 12 clinics throughout the world, including South Africa, east Africa, the United States and Thailand and found to be safe. The participants were all between the ages of 18 to 50 who didn’t have HIV and were healthy. They got four vaccinations over the span of 48 weeks. All vaccine combinations produced the anti-HIV response. The success means the vaccine can move forward with testing. This includes testing the drug on a much larger group of people. Study co-author Dr. Dan H. Barouch, a principal investigator on the study, professor of medicine at Harvard Medical School and the director of the Center for Virology and Vaccine Research observed: “We have to acknowledge that developing an HIV vaccine is an unprecedented challenge, and we will not know for sure whether this vaccine will protect humans.” In other words, the ability to induce an HIV-specific immune response doesn’t mean that it will prevent humans from getting HIV itself. For the next step, researchers are launching a new vaccine trial that will include 2,600 women in southern Africa who are at risk of HIV infection. There is a hope to report good results.