In December, participants in South Africa received their first doses in a clinical trial of a promising new HIV vaccine strategy, IAVI announced. Traditional HIV vaccine candidates have failed in trials to date, leading researchers to explore more sophisticated approaches. Germline targeting uses a series of vaccines to train immature B cells to produce broadly neutralizing antibodies (bnAbs) that target the virus. The IAVI G004 trial will examine safety and immune response to specialized immunogens designed to encourage production of bnAbs. The immunogens—dubbed OD-GT8 60mer (mRNA-1644), core-g28v2 60mer and N332-GT5 gp151—were developed at Scripps Research in California and are delivered using Moderna’s mRNA technology. In the new Phase I trial, conducted by African investigators, 96 healthy HIV-negative adults will receive various doses of the vaccine immunogens to identify the lowest doses that elicit an immune response while minimizing the risk of side effects, such as skin reactions, seen in an earlier study.