New concepts in HIV-1 vaccine development.

With 2 million people newly infected with HIV-1 in 2014, an effective HIV-1 vaccine remains a major public health priority. HIV-1 vaccine efficacy trials in humans, complemented by active and passive immunization studies in non-human primates, have identified several key vaccine-induced immunological responses that may correlate with protection against HIV-1 infection. Potential correlates of protection in these studies include V2-specific, polyfunctional, and broadly neutralizing antibody responses, as well as effector memory T cell responses. Here we review how these correlates of protection are guiding current approaches to HIV-1 vaccine development. These approaches include improvements on the ALVAC-HIV/AIDSVAX B/E vaccine regimen used in the RV144 clinical trial in Thailand, adenovirus serotype 26 vectors with gp140 boosting, intravenous infusions of bNAbs, and replicating viral vectors.