By revealing how these molecules — called broadly neutralizing antibodies — develop, the research could inform efforts to make vaccines that elicit similar antibodies that can protect people from becoming infected with HIV. The researchers, led by Barton Haynes of Duke University School of Medicine in Durham, North Carolina, found that broadly neutralizing antibodies developed only after the population of viruses in the patient had diversified — something that had been suspected of occurring in patients, but had not actually been observed. The team reports its findings on Nature's website today1.

“This is a really beautiful demonstration,” says William Schief, a protein engineer specializing in vaccine design at the Scripps Research Institute in La Jolla, California. “It poses the question for the vaccine-design field of how much of that viral diversity we need to incorporate into our vaccine regimens to try to elicit broadly neutralizing antibodies.”

HIV mutates so frequently that it has been extremely difficult to design vaccines that recognize enough forms of the virus to be effective. For the past decade, HIV-vaccine designers have tried to make progress by studying broadly neutralizing antibodies, hoping to understand what gives these molecules their ability to bind to and recognize many different HIV viruses.