Clinical trial data have shown that oral pre-exposure prophylaxis (PrEP) is efficacious when taken as prescribed; however, PrEP adherence is complex and must be understood within the context of variable risk for HIV infection and use of other HIV prevention methods. Different levels of adherence may be needed in different populations to achieve HIV prevention, and the optimal methods for achieving the necessary adherence for both individual and public health benefits are unknown. Guidance for PrEP use must consider these questions to determine the success of PrEP-based HIV prevention programs. In this article, we propose a new paradigm for understanding and measuring PrEP adherence, termed prevention-effective adherence, which incorporates dynamic HIV acquisition risk behaviors and the use of HIV alternative prevention strategies. We discuss the need for daily PrEP use only during periods of risk for HIV exposure, describe key issues for measuring and understanding relevant behaviors, review lessons from another health prevention field (i.e., family planning), and provide guidance for prevention-effective PrEP use. Moreover, we challenge emerging calls for sustained, near perfect PrEP adherence regardless of risk exposure and offer a more practical and public health-focused vision for this prevention intervention.

An interactive text-messaging intervention had high acceptability and significantly increased study-visit retention and PrEP adherence among young individuals at risk for HIV acquisition.

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Introduction: To guide future preexposure prophylaxis (PrEP) implementation for women who inject drugs (WWID), a population increasingly represented in new HIV cases in the United States, we present results from a demonstration project integrated within a syringe services program (SSP) in Philadelphia, PA. Methods: WWID ≥18 years were educated about and offered 24 weeks of daily PrEP. Participants completed surveys and clinical assessments at baseline and at weeks 1, 3, 12, and 24. We used descriptive statistics to estimate feasibility/acceptability, engagement in the care cascade, HIV/sexually transmitted diseases (STI) and pregnancy, issues of safety/tolerability, and preferences/satisfaction with PrEP services. Multivariable logistic regression with generalized estimating equations was used to identify factors associated with PrEP uptake and retention. Results: We recruited 136 WWID. Of those, 95 were included in the final sample, and 63 accepted a PrEP prescription at week 1. Uptake was associated with greater baseline frequency of SSP access [adjusted odds ratio (aOR) = 1.85; 95% confidence interval (CI): 1.24 to 2.77], inconsistent condom use (aOR = 3.38; 95% CI: 1.07 to 10.7), and experiencing sexual assault (aOR = 5.89; 95% CI: 1.02, 33.9). Of these 95, 42 (44.2%) were retained at week 24. Retention was higher among women who reported more frequent baseline SSP access (aOR = 1.46; 95% CI: 1.04 to 2.24). Self-reported adherence was high but discordant with urine-based quantification of tenofovir. Baseline STI prevalence was 17.9%; there were 2 HIV seroconversions and 1 pregnancy. Safety/tolerability issues were uncommon, and acceptability/satisfaction was high. Conclusions: Integrating PrEP with SSP services is feasible and acceptable for WWID. This suggests that daily PrEP is a viable prevention tool for this vulnerable population.

Background Intracellular tenofovir diphosphate (TFV-DP) concentration measured in dried blood spots (DBS) is used to monitor cumulative adherence to pre-exposure prophylaxis (PrEP). We evaluated TFV-DP in DBS following daily oral PrEP (emtricitabine 200mg/tenofovir diphosphate 300mg) among pregnant and postpartum adolescent girls and young women (AGYW). Methods Directly observed PrEP was administered for 12 weeks in a pregnancy group (14-24 weeks gestation, n=20) and a postpartum group (6-12 weeks postpartum, n=20) of AGYW aged 16-24 years in sub-Saharan Africa. Weekly DBS TFV-DP was measured by validated liquid chromatography-tandem mass spectrometry assay. Week 12 TFV-DP distributions were compared between groups with the Wilcoxon test. Population pharmacokinetic models were fit to estimate steady-state concentrations and create benchmarks for adherence categories. Baseline correlates of TFV-DP were evaluated. Results Participant median age was 20 years (IQR:19,22). Of 3360 doses, 3352 (>99%) were directly observed. TFV-DP median half-life was ten days (IQR:7, 12) in pregnancy and 17 days (IQR:14, 21) postpartum, with steady-state achieved by five and eight weeks, respectively. Observed median steady-state TFV-DP was 965 fmol/punch (IQR:691, 1166) in pregnancy vs 1406 fmol/punch (IQR:1053, 1859) postpartum (p=0.006). Modelled median steady-state TFV-DP was 881 fmol/punch (IQR: 667,1105) in pregnancy vs 1438 fmol/punch (IQR: 1178,1919) postpartum. In pooled analysis, baseline creatinine clearance was associated with observed TFV-DP concentrations. Conclusion TFV-DP in African AGYW was approximately one-third lower in pregnancy than postpartum. Population-specific benchmarks provided by this study can be used to guide PrEP adherence support in pregnant/postpartum African women.

Stigma regarding HIV pre-exposure prophylaxis (PrEP) is commonly implicated as a factor limiting the scale-up of this highly effective HIV prevention modality. To quantify and characterize PrEP stigma, we developed and validated a brief HIV PrEP Stigma Scale (HPSS) among a group of 279 men who have sex with men (MSM). Scale development was informed by a theoretical model to enhance content validity. We assessed two scale versions, Semantic Differential and Likert, randomizing the order in which scales were presented to participants. Both scales demonstrated high internal consistency. The Likert scale had substantially better construct validity and was selected as the preferred option. Scale scores demonstrated construct validity through association with constructs of interest: healthcare distrust, HIV knowledge, perceived proportion of friends/partners on PrEP, perceived community evaluation of PrEP, and perceived effectiveness of PrEP. The scale accounted for 25% of the total variance in reported willingness to be on PrEP, indicating the substantial role PrEP stigma may have on decisions to initiate PrEP. Given increased efforts to roll-out PrEP, having a valid tool to determine the level and types of PrEP stigma in individuals, groups, and communities can help direct implementation plans, identify goals for stigma reduction, and monitor progress over time.

IntroductionStimulant and heavy alcohol use are prevalent and associated with elevated risk for HIV seroconversion among men who have sex with men (MSM) and transgender women. In addition, each can pose difficulties for antiretroviral adherence among people living with HIV. Scant research has examined the associations of stimulant and heavy alcohol use with adherence to daily oral pre‐exposure prophylaxis (PrEP) among MSM and transgender women. To address this gap in the literature, we evaluated the hypothesis that stimulant use and binge drinking are prospectively associated with sub‐optimal PrEP adherence.MethodsWe analysed data from participants in a nested case‐cohort in the iPrEx open label extension. Stimulant use (i.e. powder cocaine, crack‐cocaine, cocaine paste, methamphetamine, cathinone) and binge drinking (i.e. ≥5 drinks in a single day) in the last 30 days were assessed. Baseline urine was tested for stimulants using immunoassays to reduce misclassification. Sub‐optimal adherence was defined as tenofovir drug concentrations in dried blood spots less than 700 fmol per punch, indicative of less than four doses per week. We tested the prospective association of stimulant use and binge drinking with sub‐optimal adherence at the 4‐week follow‐up visit.Results and DiscussionData from 330 participants were analysed. The majority of the participants were MSM (89%) with a median age at baseline of 29 years (interquartile range 24 to 39). Approximately 16% (52/330) used stimulants and 22% (72/330) reported binge drinking in the last 30 days. Stimulant users had fivefold greater odds of sub‐optimal PrEP adherence compared to non‐users in adjusted analysis (adjusted odds ratio [aOR] 5.04; [95% CI 1.35 to 18.78]). Self‐reported binge drinking was not significantly associated with sub‐optimal adherence after adjusting for stimulant use and baseline confounders (aOR 1.16 [0.49 to 2.73]). Depressive symptoms, being transgender, and number of sex partners were also not significantly associated with sub‐optimal PrEP adherence (p > 0.05).ConclusionsStimulant use is a risk factor for sub‐optimal PrEP adherence in the month following PrEP initiation. Comprehensive prevention approaches that reduce stimulant use may optimize PrEP adherence. Creating adherence plans that specifically address PrEP dosing in the context of ongoing stimulant use should also be considered.

HIV prevention interventions by clinicians treating HIV-positive patients can and should be integrated into routine clinical care.