Researchers in the Irvine and Hammond labs have developed a novel kind of vaccine adjuvant: a nanoparticle that can help to stimulate the immune system to generate a stronger response to a vaccine. These nanoparticles contain saponin, a compound derived from the bark of the Chilean soapbark tree, along with a molecule called MPLA, each of which helps to activate the immune system. The adjuvant has been incorporated into an experimental HIV vaccine that has shown promising results in animal studies, and this the first human volunteers will receive the vaccine as part of a phase 1 clinical trial run by the Consortium for HIV/AIDS Vaccine Development at the Scripps Research Institute.