HIV vaccines: current approaches and new developments

The challenge of developing an acquired immune deficiency syndrome (AIDS) vaccine continues to be paramount as the global AIDS epidemic progresses. Traditional vaccine strategies that induce broadly neutralizing antibodies have so far been ineffective, and focus is now turning toward more novel approaches that seek to elicit T-lymphocyte responses. Recent results from the STEP vaccine trial, a test-of-concept trial of an adenoviral serotype 5-based vaccine, failed to show a protective effect despite clear induction of human immunodeficiency virus (HIV) immunogenicity and early promising results in nonhuman primate studies. The results from the STEP trial demonstrate that innovative approaches and a better understanding of the immunopathogenesis of HIV disease are needed for the goal of a safe, globally effective HIV vaccine to be realized.