Acceptability of tenofovir gel as a vaginal microbicide among women in a phase I trial a mixed-methods study,

THE GLOBAL HIV EPIDEMIC increasingly affectswomen.1 For most, the only risk factor for becominginfected is the behavior of their male sexualpartners.1 Condoms often are unacceptableand insufficiently used,2–4 gender-based powerimbalances can make them difficult to negotiate,4–7 and religious beliefs, fertility needs, fear ofimplied infidelity, and preferences for sex withouta barrier are challenges to their acceptabilityand use. Women-initiated HIV prevention methodsare urgently needed, making the developmentof vaginal microbicides that reduce the likelihoodof sexual transmission of HIV a majorpublic health priority.First-generation vaginal microbicides will mostlikely be topical gels inserted into the vagina withan applicator. A variety of microbicides is currentlyunder development, and six have enteredlate-stage clinical trials.8–12 Initial product acceptabilityhas been assessed in clinical trials,13–16 surveysof product attributes among potentialusers17,18 and their partners,19 and studies that useover-the-counter (OTC) surrogates or placebo gelwith presumed similar formulation and applicationcharacteristics as eventual products.20–23 Acceptabilityassessments in early clinical trials areespecially important because their findings can influencefurther development of the product.Here, we report on acceptability data amongwomen participating in a phase I trial of tenofovirgel, a candidate microbicide that inhibits HIV reversetranscriptase. Details of the trial are reportedelsewhere,24 as is acceptability amongmale partners of trial participants.25 This was thefirst human trial of a topical antiretroviral thatspecifically inhibits a necessary replication stepin the HIV life cycle. Interest in this approach toHIV prevention has increased in recent yearssince efficacy trials of a topical surfactant(nonoxynyl-9) and a nonspecific inhibitor of HIVbinding (cellulose sulfate) indicated that thesetwo types of compounds were not protective andpotentially increased HIV transmission in womenwho had frequent sexual exposures to HIV. Severallarger-scale, expanded safety and proof-ofconcepttrials of tenofovir gel are now underway,based in part on the safety, tolerability, and acceptabilityof this microbicide demonstrated inthe study described in this paper.