Progress in HIV vaccine research: an outsider's view

Despite the potential for pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP) to have a significant impact on HIV transmission, there is broad agreement that a safe and effective preventive vaccine remains an essential tool for ending the AIDS epidemic. To date, progress towards a vaccine has been painstaking. Nevertheless, recent progress has opened up promising new leads. Results of the STEP and RV-144 trials provide novel insights that may lead to improved design of candidate vaccines. In addition, the identification of highly potent, broadly neutralizing monoclonal antibodies from some infected patients suggests novel approaches to generating protective immunity. Refinements in our understanding of the gp120 structure and its interaction with CD4 also provide opportunities for improving immunogen design. Although the challenges remain daunting, these advances have instilled a renewed sense of optimism into the field.