(The following summary is excerpted and adapted from the article's abstract):
The results of the CAPRISA 004 and iPrEx HIV prevention studies have demonstrated that topical or systemic use of antiretroviral agents can significantly reduce the risk of HIV acquisition associated with unprotected vaginal or anal sexual intercourse. However, the effect size in these studies was relatively modest and product adherence was generally poor. These observations suggest the need for new approaches to HIV prevention, especially for MSM characterized as "high risk". Rates of lubricant use are high in MSM practicing receptive anal sex. Consequently, the development of an antiretroviral rectal microbicide gel may provide a safe and effective means of preventing HIV infection with an intervention that is likely to have high acceptability among the target population. The purpose of this article is to describe the challenges and progress in the development of rectal microbicides for HIV prevention.