Editorial: Critical social and behavioral sciences perspectives on ending the HIV epidemic.

Recent development of highly efficacious long-acting, injectable drugs to prevent and treat HIV have excited the world. At the same time, the reticence of a significant proportion of the eligible population to use these technologies and the existence of major faults in the systems through which these technologies are distributed to those who do want them give us all pause. The tension between the possibility of new discoveries and the reality of their uptake and use (or lack thereof) at its core reflects the tension between ‘efficacy’ and ‘effectiveness’. Although a technology may prove highly efficacious for individuals in a controlled research environment, when it hits the ‘real world’, its true effectiveness in a population is contingent on physical, psychological, and social (including political, economic, and cultural) and behavioral factors that influence its adoption and impact [1]. These factors play out differentially across societies, although there are some common features.