Two sides to the HIV prevention coin: efficacy and effectiveness.

In the context of the current concern about HIV prevention efforts, this article addresses the issues of efficacy and effectiveness. We argue that the success of treatments and associated increasing dominance of biomedicine has meant that far too little attention has been paid to effectiveness, that is, to the impact an HIV prevention program or intervention achieves in the real world, under resource constraints, in entire populations. Although biomedicine has, appropriately, investigated the efficacy of a number of new prevention technologies and modeled the impact of "test and treat," issues relating to the provision, acceptability, adoption, and sustained use of prevention technologies, both old and new, have not been fully addressed.

What part of HIV prevention conversations don't we understand?

There has been much discussion, particularly in the wake of analyses of the World Health Organization's 3 by 5 programme, about the place of prevention in responses to HIV. While 3 by 5 focussed on improved access to treatment for people living with HIV and AIDS, its successor 'Universal Access' explicitly acknowledged that if we are to make any significant impact on the HIV pandemic then programme scale-up must include prevention and care. HIV prevention is not just about minimising the risk of disease transmission from an infected individual to another.