Biomedical prevention of sexually transmitted HIV

The control of the HIV epidemic is a momentous challenge. Despite successes in some situations, HIV transmission has not been adequately reduced by the HIV prevention methods currently available. This is demonstrated by the continuing spread of the HIV epidemic, mainly through sexual transmission. The approaches to HIV prevention have broadly been defined as structural, behavioural and biomedical. The objectives of this thesis were to examine the personal and public health impact of selected biomedical HIV prevention technologies on HIV acquisition and HIV risk behaviour and to explore a number of the specific scientific and methodological challenges encountered in the field of development of HIV prevention technologies. The following research aimed to add to the available Australian data on biomedical HIV prevention, and to determine the potential for future trials of HIV biomedical prevention in Australia.A number of key findings from this thesis contribute to knowledge in the area of biomedical HIV prevention research. Firstly, the design of published safety studies of candidate vaginal microbicides was not sufficient to detect potential toxic effects of these products. A second important contribution was the demonstration that there was no evidence of behavioural disinhibition after non-occupational post-exposure prophylaxis for HIV (NPEP) use. Thirdly, NPEP had an important protective effect against HIV acquisition at an individual level but not at a population level. Fourth, groups with high HIV incidence could be readily identified in low HIV incidence settings. Finally, men with higher levels of HIV risk were more willing to participate in clinical trials of biomedical HIV prevention technologies.The research in this thesis underlines the complex nature of biomedical HIV prevention research and HIV prevention implementation, from the design of clinical trials of candidate biomedical HIV prevention products, to identifying suitable study populations who are willing to take part in such trials and finally to implementing the use of such technologies. HIV prevention remains a global public health priority and it is imperative that efforts to identify safe and effective biomedical HIV prevention technologies continue

Baseline Preferences for Daily, Event-Driven, or Periodic HIV Pre-Exposure Prophylaxis among Gay and Bisexual Men in the PRELUDE Demonstration Project

IntroductionThe effectiveness of daily pre-exposure prophylaxis (PrEP) is well established. However, there has been increasing interest in non-daily dosing schedules among gay and bisexual men (GBM). This paper explores preferences for PrEP dosing schedules among GBM at baseline in the PRELUDE demonstration project.Materials and methodsIndividuals at high-risk of HIV were enrolled in a free PrEP demonstration project in New South Wales, Australia, between November 2014 and April 2016. At baseline, they completed an online survey containing detailed behavioural, demographic, and attitudinal questions, including their ideal way to take PrEP: daily (one pill taken every day), event-driven (pills taken only around specific risk events), or periodic (daily dosing during periods of increased risk).ResultsOverall, 315 GBM (98% of study sample) provided a preferred PrEP dosing schedule at baseline. One-third of GBM expressed a preference for non-daily PrEP dosing: 20% for event-driven PrEP, and 14% for periodic PrEP. Individuals with a trade/vocational qualification were more likely to prefer periodic to daily PrEP [adjusted odds ratio (aOR) = 4.58, 95% confidence intervals (95% CI): (1.68, 12.49)], compared to individuals whose highest level of education was high school. Having an HIV-positive main regular partner was associated with strong preference for daily, compared to event-driven PrEP [aOR = 0.20, 95% CI: (0.04, 0.87)]. Participants who rated themselves better at taking medications were more likely to prefer daily over periodic PrEP [aOR = 0.39, 95% CI: (0.20, 0.76)].DiscussionIndividuals’ preferences for PrEP schedules are associated with demographic and behavioural factors that may impact on their ability to access health services and information about PrEP and patterns of HIV risk. At the time of data collection, there were limited data available about the efficacy of non-daily PrEP schedules, and clinicians only recommended daily PrEP to study participants. Further research investigating how behaviours and PrEP preferences change correspondingly over time is needed.Trial registrationClinicalTrials.gov NCT02206555. Registered 28 July 2014