HIV vaccine design: the neutralizing antibody conundrum

► Broadly neutralizing antibodies against HIV are generated during infection, but so far, not by vaccination. ► Recently, MAbs with potent and broad anti-HIV neutralizing activities were isolated from HIV-infected subjects. ► The study of these new MAbs informs us on their ontogenicity, structures, epitope-recognition and mechanisms of action. ► New approaches on how to elicit similar antibodies by immunization, are discussed.