What Immunity Can Protect against HIV Infection? Editorial

The successful development of any protective vaccine requires a knowledge of the immune correlates of protection. Rational targets for vaccine-elicited immune responses can only be es-tablished with an understanding of the immune responses that provide protection against infection by a pathogen. Defining such immune correlates of protection against HIV has proven extraordinarily difficult. Although powerful nonhuman pri-mate models for HIV infection exist, impressive protection against AIDS virus challenges in these models has been diffi-cult to achieve using safe, traditional vaccine strategies (1). Therefore, the results of studies done in nonhuman primates do not allow us to state with any degree of confidence whether humoral or cellular immunity will be needed to achieve pro-tection against exposure to HIV. The few reported cohorts of multiply exposed HIV seronegative individuals are a focus o