Study designs for identifying risk compensation behavior among users of biomedical HIV prevention technologies: balancing methodological rigor and research ethics

The potential effect of pre-exposure prophylaxis (PrEP) roll-out on sexual-risk behaviour among adolescents and young people in East and southern Africa

Pre-exposure prophylaxis (PrEP) is an HIV-prevention strategy recommended for those at high-risk of infection, including adolescents and young people (AYP). We explored how PrEP roll-out could influence sexual risk behaviour among AYP in East and southern Africa. Twenty-four group discussions and 60 in-depth interviews were conducted with AYP between 13 and 24 years old, recruited from community settings in Uganda, Zimbabwe and South Africa, from September 2018 to January 2019. Participants perceived that PrEP availability could change sexual behaviour among AYP, influencing: (1) condom use (increased preference for condomless sex, reduced need and decrease in use of condoms, relief from condom use discomfort, consistent condom use to curb sexually transmitted infections and pregnancies); (2) sexual activities (increase in sexual partners and sexual encounters, early sexual debut, sexual experimentation and peace of mind during risky sex, sexual violence and perversion); (3) HIV risk perception (neglect of other HIV prevention strategies, unknown sexual partner HIV status, adoption of PrEP). PrEP initiation may be associated with increased interest in sexual activities and risky sexual behaviour among AYP. PrEP should be included as part of a combination package of HIV prevention strategies for AYP with methods to prevent other sexually transmitted infections and unwanted pregnancies.

HIV Pre-Exposure Prophylaxis, Condoms, or Both? Insights on Risk Compensation Through a Discrete Choice Experiment and Latent Class Analysis Among Men Who Have Sex With Men

OBJECTIVES

We considered how decision making around human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP) among gay, bisexual, and other men who have sex with men (GBMSM) is made in the context of one's perceived risk of HIV acquisition and the availability of condoms.

METHODS

We recruited 648 GBMSM aged 18 years old and residing in Singapore through Grindr. Participants were given information on PrEP and participated in a discrete choice experiment requiring them to choose between 2 baskets of PrEP attributes and compare the chosen "PrEP only" option to default options of "condoms only" or "PrEP with condoms." Generalized multinomial logit model was used to examine the scaling effect and preference heterogeneity. Latent class analysis was conducted to examine preference heterogeneity in the sample.

RESULTS

Latent class analysis revealed 3 classes of GBMSM: PrEP conservatives (53.9%), moderates (31.1%), and liberals (14.9%). PrEP conservatives were more likely to report greater utility when using condoms only compared with PrEP only, as well as PrEP with condoms, compared with PrEP only, and more likely to report the lowest utility for PrEP as perceived HIV risk increased. PrEP liberals were more likely to report greatest utilities for PrEP only compared with condoms only, as well as PrEP only compared with PrEP with condoms. The utility for PrEP was not affected by perceived risk of HIV or sexually transmitted infections when risks were low.

CONCLUSION

This study provides some evidence for risk compensation among a class of GBMSM who already perceived themselves to be good candidates for PrEP before the discrete choice experiment.

The impact of PrEP: results from a multicenter Health Technology Assessment into the Italian setting

INTRODUCTION

The use of oral tenofovir/emtricitabine (FTC/TDF) for pre-exposure prophylaxis (PrEP) among high-risk people without Human Immunodeficiency Virus (HIV), is emerging as an innovative strategy to decrease HIV epidemic. The study aims at evaluating the implications related to PrEP introduction, from a multidimensional point of view, as required by Health Technology Assessment (HTA) approach, with a particular attention on sustainability and social factors, influencing PrEP implementation.

METHODS

An analysis was conducted involving 35 Italian Infectious Disease Departments. The introduction of PrEP (applied both as "add-on" and "substitute" prevention strategy) into the clinical practice was compared with a baseline scenario, consisting of condoms among men who have sex with men, and serodiscordant couples, and the use of Needle Syringe Programme among injection drugs users The above scenarios were analysed by means of a Health Technology Assessment (HTA) approach. The 9 EUnetHTA Core Model domains were assessed through comparative information, retrieved from literature evidence, and collection of qualitative and quantitative information, derived from real-world evidence, in particular from 35 Infectious Disease Departments and potential PrEP' users involved. A final multi-criteria decision analysis approach (MCDA) was implemented to simulate the appraisal phase and providing evidence-based information with regard to the preferable technology.

RESULTS

Despite the improvement in patients' quality of life, PrEP would generate the development of other sexually transmitted and blood-borne diseases, with a consequent decrease of patients' safety in case of PrEP applied as a "substitute" prevention strategy. In addition, PrEP would generate an increase in staff workflow, with investment in medical supplies and training courses. PrEP would lead to significant economic investments both for the NHS (+40%), and for citizens (+2,377%) if used as an add-on strategy, assuming FTC/TDF patent cost. With the off-patent drug, the NHS would benefit from an advantage (37%), and a shrink of the patients' expenditure emerged (+682%). More economic resources are required if PrEP is applied as a substitute strategy, considering both the patent (NHS: 212%; citizens: 3,423%) and the off-patent drug (NHS: 73%; citizens: 1,077%). Conclusions. The most cost-containing strategy would be the use of PrEP, as an add-on strategy, with a consequent improvement in patients' safety, even if drug-related adverse events would be considered. The implementation of the off-patent drug would decrease the economic burden of the innovative prevention strategy. Hence, the organizational aspects related to its adoption would be deeply investigated, with the potential opportunity to create specific ambulatories devoted to PrEP users' especially for medium and big size hospitals.

PrEP Use Among Female Sex Workers: No Evidence for Risk Compensation

Supplemental Digital Content is Available in the Text.

Little is known about risk compensation among female sex workers (FSW) on HIV pre-exposure prophylaxis (PrEP), and self-report of sexual behaviors is subject to bias.

Ethics of Conducting Clinical Research in an Outbreak Setting

The conduct of clinical trials during the West Africa Ebola outbreak in 2014 highlighted many ethical challenges. How these challenges were addressed, what clinical studies were conducted during that outbreak, and the lessons learned for dealing with future outbreaks were the subject of a National Academy of Medicine committee report titled Integrating Clinical Research into Epidemic Response: The Ebola Experience. This report suggested improvements for research during subsequent emerging or re-emerging outbreaks and is summarized in this review. We also discuss the current Ebola outbreak in the Democratic Republic of the Congo and highlight how the dialogue has changed and how successful clinical trials have been implemented. We conclude with a description of productive efforts to include pregnant women and children in therapeutic and vaccine trials during outbreaks that are currently ongoing.

Personal Genetic Information about HIV: Research Participants' Views of Ethical, Social, and Behavioral Implications

BACKGROUND

Personal genetic information (PGI) about HIV is produced in research and entering the clinic and direct-to-consumer market, but little consideration has been given to ethical and social issues, public perspectives, and potential behavioral implications.

OBJECTIVES

This research queried the views of research participants at risk for or infected with HIV, exploring their perspectives on HIV-related PGI and its ethical, social, and behavioral implications.

METHODS

We used focus groups to collect rich information about participants' perspectives on the ethical, social, and behavioral implications of PGI about HIV and host genetic research. We evaluated their reactions to three different types of genetic variants: those that made them more susceptible to HIV, more protected from or resistant to HIV, or more likely to transmit HIV to others.

RESULTS

Overall, participants wanted PGI about HIV. Their reasons included a mix of personal or family health benefit and benefit to others, which varied in emphasis depending on variant type. While susceptibility variant information was seen primarily in terms of personal or family health benefit, for transmissibility and protective variant information, benefit to others emerged as a major reason for wanting PGI about HIV. Participants thought transmissibility variant information would help them prevent others from becoming infected, and protective variant information would allow them to volunteer for targeted research to help treat, cure, or prevent HIV. Possible harms were raised regarding the tendencies among some individuals to increase risky behavior with modulations in perceived risk. Potential behavioral implications were seen as significant, though complex, reflecting multifaceted risk perceptions.

CONCLUSIONS

Our study adds to the evidence that participants in genetic research, across disease type, have a strong desire for PGI. For participants in research on the genetics of HIV, and potentially other infectious diseases, their desire for PGI is grounded in a perceived duty not to infect others, where they feel a moral responsibility regarding research participation and behavior change. Wider dissemination of HIV-related PGI may well increase research participation, but could have mixed effects on risk behavior. More research is needed on the implications of different variant types of PGI beyond susceptibility factors, especially protective variants or resistance factors.

Give PrEP a chance: moving on from the "risk compensation" concept

INTRODUCTION

While bio-behavioural interventions (BIs) for sexually transmitted infections (STIs) and HIV prevention have shown their effectiveness (e.g. treatment for syphilis, HPV vaccination or pre-exposure prophylaxis [PrEP]), they have also aroused major concerns regarding behavioural changes that could counteract their benefit. Risk compensation (RC) fears concerning BIs in the HIV/STIs prevention field are intimately linked to representations, judgements and social control on sexual behaviour. With an increasing number of PrEP studies describing a rise in STIs due to RC, this paper argues for a shift away from the focus on RC and proposes a more constructive approach to respond to the needs of people living with HIV and populations most at risk.

DISCUSSION

The concept of RC, stemming from road safety and derived from economic theory, relies on rational theoretical models of human behaviour. Although widely applied in several contexts its use has been reasonably questioned. Major methodological issues regarding RC have been raised within HIV/AIDS literature. Although behavioural changes (e.g. condomless sex and number of sexual partners) are often erroneously assimilated with RC, there is no evidence that behavioural changes have undermined the effectiveness of previous and current BIs. Still, PrEP has not escaped RC concerns. Increases in condomless sex within the context of growing uptake of PrEP signals a continued need for integrated and innovative HIV and STI prevention strategies and a comprehensive sexual health approach. Routine HIV/STI testing, peer-led counselling, and identification of sexual health needs within the PrEP model of care could become a gold standard in the sexual health field for all populations.

CONCLUSIONS

RC remains a frequent argument against the availability and provision of prevention methods for vulnerable populations. Individuals should be able to benefit from the full panel of BIs options available, to find and adapt methods according to their needs. Current, past and future PrEP users, with other stakeholders, may provide valuable insight into innovative solutions and programmes to control HIV and other STIs.

How safe is TDF/FTC as PrEP? A systematic review and meta-analysis of the risk of adverse events in 13 randomised trials of PrEP

BACKGROUND

Tenofovir/emtricitabine (TDF/FTC) used as pre-exposure prophylaxis (PrEP) has proven benefits in preventing HIV infection. Widespread use of TDF/FTC can only be justified if the preventative benefits outweigh potential risks of adverse events. A previous meta-analysis of TDF/FTC compared to alternative tenofovir alafenamide (TAF)/FTC for treatment found no significant difference in safety endpoints when used without ritonavir or cobicistat, but more evidence around the safety of TDF/FTC is needed to address concerns and inform widespread use.

METHODS

A systematic review identified 13 randomised trials of PrEP, using either TDF/FTC or TDF, versus placebo or no treatment: VOICE, PROUD, IPERGAY, FEM-PrEP, TDF-2, iPrEX, IAVI Kenya, IAVI Uganda, PrEPare, PARTNERS, US Safety study, Bangkok TDF study, W African TDF study. The number of participants with grade 3/4 adverse events or serious adverse events (SAEs) was compared between treatment and control in the meta-analysis. Further analyses of specific renal and bone markers were also undertaken, with fractures as a marker of bone effects and creatinine elevations as a surrogate marker for renal impairment. Analyses were stratified by study duration (</>1 year of follow up).

RESULTS

The 13 randomised trials included 15,678 participants in relevant treatment and control arms. Three studies assessed TDF use only. The number of participants with grade 3/4 adverse events was 1306/7504 (17.4%) on treatment versus 1259/7502 (16.8%) on control (difference=0%, 95% confidence interval [CI] -1% to +2%). The number of participants with SAEs was 740/7843 (9.4%) on treatment versus 795/7835 (10.1%) on no treatment (difference=0%, 95% CI -1% to +1%). The number of participants with creatinine elevations was 8/7843 on treatment versus 4/7835 on control (difference=0%, 95% CI 0%-0%). The number of participants with bone fractures was 217/5789 on treatment versus 189/5795 on control (difference=0%, 95% CI 0% to 1%). There was no difference in outcome between studies with <1 versus >1 year of randomised treatment.

CONCLUSIONS

In this meta-analysis of 13 randomised clinical trials of PrEP in 15,678 participants, there was no significant difference in risk of grade 3/4 clinical adverse events or SAEs between TDF/FTC (or TDF) and control. Furthermore, there was no significant difference in risk of specific renal or bone adverse outcomes. The favourable safety profile of TDF/FTC would support more widespread use PrEP in populations with a lower risk of HIV infection.

Sex, human rights and AIDS: an analysis of new technologies for HIV prevention in the Brazilian context

Worldwide, HIV prevention is challenged to change because clinical trials show the protective effect of technologies such as circumcision, preexposure prophylaxis, and the suppression of viral load through antiretroviral treatment. In the face of demands for their implementation on population levels, the fear of stimulating risk compensation processes and of increasing riskier sexual practices has retarded their integration into prevention programs. In this article, following a narrative review of the literature on risk compensation using the PubMed database, we offer a critical reflection on the theme using a constructionist approach of social psychology integrated to the theoretical framework of vulnerability and human rights. The use of biomedical technologies for prevention does not consistently induce its users to the increase of riskier practices, and variations on the specificity of each method need to be carefully considered. Alternatives to the theories of sociocognitive studies, such as social constructionist approaches developed in the social sciences and humanities fields, indicate more comprehensive interpretations, valuing the notions of agency and rights. The critical analysis suggests priority actions to be taken in the implementation process: development of comprehensive programs, monitoring and fostering dialog on sexuality, and technical information. We highlight the need to implement a human rights-based approach and to prioritize dialog, stressing how complementary these technologies can be to meet different population needs. We conclude by stressing the need to prioritize sociopolitical changes to restore participation, dialog about sexuality, and emphasis on human rights such as core elements of the Brazilian AIDS policy.

Divergent Preferences for HIV Prevention: A Discrete Choice Experiment for Multipurpose HIV Prevention Products in South Africa

BACKGROUND

The development of antiretroviral (ARV)-based prevention products has the potential to substantially change the HIV prevention landscape; yet, little is known about how appealing these products will be outside of clinical trials, as compared with the existing options.

METHODS

We conducted a discrete choice experiment (DCE) to measure preferences for 5 new products among 4 important populations in the HIV response: adult men and women in the general population (aged 18 to 49 y), adolescent girls (aged 16 to 17 y), and self-identifying female sex workers (aged 18 to 49 y). We interviewed 661 self-reported HIV-negative participants in peri-urban South Africa, who were asked to choose between 3 unique, hypothetical products over 10 choice sets. Data were analyzed using multinomial, latent class and mixed multinomial logit models.

RESULTS

HIV protection was the most important attribute to respondents; however, results indicate significant demand among all groups for multipurpose prevention products that offer protection from HIV infection, other STIs, and unwanted pregnancy. All groups demonstrated a strong preference for long-lasting injectable products. There was substantial heterogeneity in preferences within and across population groups.

LIMITATIONS

Hypothetical DCE data may not mirror real-world choices, and products will have more attributes in reality than represented in choice tasks. Background data on participants, including sensitive areas of HIV status and condom use, was self-reported.

CONCLUSIONS

These results suggest that stimulating demand for new HIV prevention products may require a more a nuanced approach than simply developing highly effective products. No single product is likely to be equally attractive or acceptable across different groups. This study strengthens the call for effective and attractive multipurpose prevention products to be deployed as part of a comprehensive combination prevention strategy.

Individual Versus Community-Level Risk Compensation Following Preexposure Prophylaxis of HIV

We analyzed the concept of risk compensation and how it has been applied in HIV prevention, paying particular attention to the strategy of HIV preexposure prophylaxis (PrEP). In risk compensation, reduced perceptions of risk after the introduction of a preventative intervention lead to more frequent risk-taking behavior. Such a change may undermine the intervention's protective benefits. We found that many studies purporting to investigate risk compensation do not assess or report changes in perceptions of risk, instead relying on behavioral measures. Our analysis suggests a complex and sometimes counterintuitive relationship between the introduction of a new prevention intervention, perceptions of HIV risk, and subsequent changes in behavior. As PrEP is introduced, we believe comprehensive assessment of community-level risk compensation-that is, changes in risk perceptions and behavior as a result of increased optimism about avoiding HIV among people not directly protected by PrEP-should not be omitted. We therefore suggest ways to assess prevention optimism and community-level risk compensation.

Cultural competence: a framework for promoting voluntary medical male circumcision among VaRemba communities in Zimbabwe

Almost a decade after the formal introduction of voluntary medical male circumcision (VMMC) as an important technology for HIV prevention, its implementation is still fraught with acceptability challenges. This is especially true among ethnic groups where male circumcision is conducted as a rite of passage into adulthood. In this article we question why VMMC is being met with resistance despite widespread awareness of its promise to reduce HIV incidence in a culturally circumcising community in Zimbabwe. In-depth and key informant interviews were conducted with selected VaRemba initiation graduates and surgeons respectively in Mposi area in Mberengwa to explore why VMMC has not been readily accepted in their community. Findings suggest that male circumcision among VaRemba is not only the removal of prepuce but comprises a secretive and rich curriculum rooted in their culture and identity. Such a conceptualisation renders some social and programmatic impediments for VMMC uptake. To scale up VMMC uptake among VaRemba, we argue for a reorganisation and adaptation of VMMC services in a culturally competent way that accounts for local conceptions of circumcision and respect for the cultural beliefs and practices of VaRemba communities.

Evaluation of Sexual Risk Behavior Among Study Participants in the TDF2 PrEP Study Among Heterosexual Adults in Botswana

OBJECTIVE

Among participants of a clinical trial to test the efficacy of tenofovir/emtricitabine in protecting heterosexual men and women living in Botswana from HIV infection, the aim was to determine (1) if sexual risk behavior, specifically condomless sex acts and number of sex partners, changed over time, (2) factors associated with condomless sex acts and number of sex partners, and (3) the effect of participant treatment arm perception on risk behavior to address the possibility of risk compensation.

METHODS

A longitudinal modeling of rates of risk behaviors was used to determine if the rate of condomless sex acts (#acts/person) and rate of sex partners (#partners/person) changed over time and which factors were associated with behavior change.

RESULTS

One thousand two hundred participants were analyzed over 1 year. There was a 25% decrease in the rate of sex partners among participants sexually active in the last 30 days. The rate of reported condomless sex acts was greater for males [rate ratio (RR) = 1.34; confidence interval (CI): 1.07 to 1.67] and participants whose sexual debut in years was ≤15 years of age (RR = 1.65; CI: 1.14 to 2.38) and 16-17 (RR = 1.68; CI: 1.22 to 2.31) compared with those ≥20 years. Rate of reported sex partners was greater for males (RR = 3.67; CI: 2.86 to 4.71) and participants whose age at sexual debut in years was ≤15 (RR = 2.92; CI: 2.01 to 4.22) and 16-17 (RR = 2.34; CI: 1.69 to 3.24) compared with those ≥20. There was no effect of participant treatment arm perception on risk behavior.

CONCLUSIONS

Our study of preexposure prophylaxis to prevent HIV infection found no evidence of risk compensation which may have been due to participants' motivations to reduce their risk behaviors and risk-reduction counseling.

Exploring evidence for behavioral risk compensation among participants in an HIV vaccine clinical trial

BACKGROUND

HIV vaccine trial participants may engage in behavioral risk compensation due to a false sense of protection. We conducted an ancillary study of an HIV Vaccine Trials Network (HVTN) vaccine efficacy trial to explore risk compensation among trial participants compared to persons who were willing to participate but ineligible based on previous exposure to the Ad5 virus (Ad5+) across three timepoints.

METHODS

Participants were drawn from the Atlanta, GA site of the HVTN 505 vaccine trial. From 2011-2013, all persons who met prescreening criteria for the clinical trial and presented for Ad5 antibody testing were invited to participate in the ancillary study. Data were collected from vaccine trial participants (n=51) and Ad5+ participants (n=60) via online surveys across three timepoints: baseline, T2 (after trial participants received 2/4 injections) and T3 (after trial participants received 4/4 injections). Data analyses assessed demographic, psychosocial, and behavioral differences at baseline and changes at each timepoint.

RESULTS

At baseline, Ad5+ participants were less likely to have some college education (p=0.024) or health insurance (p=0.008), and were more likely to want to participate in the vaccine trial "to feel safer having unprotected sex" (p=0.005). Among vaccine trial participants, unprotected anal sex with a casual partner (p=0.05), HIV transmission worry (p=0.033), and perceived chance of getting HIV (p=0.027), decreased across timepoints.

CONCLUSIONS

Study findings suggest that persons with previous exposure to Ad5 may be systematically different from their Ad5-negative peers. Unprotected anal sex with a casual partner significantly decreased among HIV vaccine trial participants, as did HIV worry and perceived chance of getting HIV. Findings did not support evidence of risk compensation among HIV vaccine trial participants compared to Ad5+ participants.

[Individuals, structures, and risks: an overview of primary HIV prevention in Portugal]

This article debates the principal guidelines and procedures that shape HIV/AIDS prevention in Portugal, focusing on risk reduction in the two major scenarios for spread of the epidemic: sexuality and injection drug use. The analysis views the risks of infection as expressions of practices that are densely interwoven into social structures and cultural frameworks. Based on this conception, the article seeks to evaluate and understand the extent to which preventive strategies take a broad and integrative underlying approach by including individuals and their circumstances. Meanwhile, the study identifies some of the main structural constraints impeding the achievement of more favorable conditions for minimizing risks and adopting safe behaviors. These analytical exercises include not only policy and program guidelines, but also processes in daily reality, showing how the non-implementation of measures already guaranteed by law poses powerful structural barriers to HIV prevention.

Effectiveness and safety of oral HIV preexposure prophylaxis for all populations

OBJECTIVE

Preexposure prophylaxis (PrEP) offers a promising new approach to HIV prevention. This systematic review and meta-analysis evaluated the evidence for use of oral PrEP containing tenofovir disoproxil fumarate as an additional HIV prevention strategy in populations at substantial risk for HIV based on HIV acquisition, adverse events, drug resistance, sexual behavior, and reproductive health outcomes.

DESIGN

Rigorous systematic review and meta-analysis.

METHODS

A comprehensive search strategy reviewed three electronic databases and conference abstracts through April 2015. Pooled effect estimates were calculated using random-effects meta-analysis.

RESULTS

Eighteen studies were included, comprising data from 39 articles and six conference abstracts. Across populations and PrEP regimens, PrEP significantly reduced the risk of HIV acquisition compared with placebo. Trials with PrEP use more than 70% demonstrated the highest PrEP effectiveness (risk ratio = 0.30, 95% confidence interval: 0.21-0.45, P < 0.001) compared with placebo. Trials with low PrEP use did not show a significantly protective effect. Adverse events were similar between PrEP and placebo groups. More cases of drug-resistant HIV infection were found among PrEP users who initiated PrEP while acutely HIV-infected, but incidence of acquiring drug-resistant HIV during PrEP use was low. Studies consistently found no association between PrEP use and changes in sexual risk behavior. PrEP was not associated with increased pregnancy-related adverse events or hormonal contraception effectiveness.

CONCLUSION

PrEP is protective against HIV infection across populations, presents few significant safety risks, and there is no evidence of behavioral risk compensation. The effective and cost-effective use of PrEP will require development of best practices for fostering uptake and adherence among people at substantial HIV risk.

Uptake of PrEP and condom and sexual risk behavior among MSM during the ANRS IPERGAY trial

The double-blind phase of the randomized ANRS IPERGAY trial, evaluating sexual activity-based oral HIV pre-exposure prophylaxis (PrEP), was conducted among high-risk men who have sex with men (MSM). Results showed an 86% (95% CI: 40–98) relative reduction in HIV incidence among participants with tenofovir disoproxil fumarate–emtricitabine vs. placebo. The present pooled analysis aimed to analyze (i) participants’ adherence to the prescribed treatment and/or condom use during sexual intercourse and (ii) sexual behavior during the double-blind phase of the study. Four hundred MSM were enrolled in the trial. Every 2 months they completed online questionnaires collecting sexual behavior and PrEP adherence data regarding their most recent sexual intercourse. A total of 2232 questionnaires (M0–M24) were analyzed. Changes over time were evaluated using a mixed model accounting for multiple measures. Irrespective of sexual partner and practice type, on average, 42.6% (min: 32.1–max: 45.8%) reported PrEP use only during their most recent episode of sexual intercourse; 29% (22.9–35.6%) reported both PrEP and condom use; 11.7% (7.2–18.9%) reported condom-use only, and 16.7% (10.8–29.6%) reported no PrEP or condom use with no significant change during the study. Scheduled (i.e., correct) PrEP use was reported on average by 59.0% (47.2–68.5%) of those reporting PrEP use during their most recent sexual intercourse. Overall, 70.3% (65.3–79.4%) and 69.3% (58.3–75.4%) of participants reported, respectively, condomless anal and condomless receptive anal intercourse during their most recent sexual encounter without significant change during follow-up. Overall, on average 83.3% (min: 70.4–max: 89.2%) of participants protected themselves by PrEP intake or condom use or both during the trial, and no increase in at-risk sexual practices was observed. None of these indicators showed significant trend during the follow-up, although we found a tendency toward decrease (p = .19) of the median number of sexual partners strengthening the absence of behavioral disinhibition. On-demand PrEP within a comprehensive HIV prevention package could improve prevention in MSM.

Effect of pre-exposure prophylaxis and combination HIV prevention for men who have sex with men in the UK: a mathematical modelling study

BACKGROUND

HIV transmission in men who have sex with men (MSM) in the UK has shown no sign of decreasing in the past decade. Additional prevention measures are needed. We aimed to estimate the effect of various potential interventions implemented individually and in combination on prevention of HIV infection.

METHODS

We extended a deterministic partnership-based mathematical model for HIV transmission, informed by detailed behavioural and surveillance data, to assess the effect of seven different HIV interventions implemented in MSM (aged 15-64 years) in the UK during 2014-20, including increasing rates of HIV testing, test-and-treat programmes, pre-exposure prophylaxis (PrEP), and sexual behavioural changes. We did sensitivity analyses on risk compensation.

FINDINGS

We predicted a baseline of 16 955 new infections (IQR 13 156-21 669) in MSM in the UK during 2014-20. At a coverage of ≤50%, testing twice a year outperformed all other interventions. Of all intervention combinations, only the combined effect of test and treat and annual HIV testing (61·8%, IQR 47·2-81·8, of total incidence) was greater than the sum of effects of the two interventions individually (32·6%, 23·7-46·0, and 23·9%, 16·5-33·3, respectively). Simultaneous PrEP, expansion of HIV testing, and initiation of test-and-treat programme in 25% of high-activity MSM could save 7399 (IQR 5587-9813) UK MSM from HIV infection (43·6%, IQR 32·9-57·9, of total incidence). An increase in unsafe sex or sexual partners to 50% or more could substantially reduce the effect of interventions, but is unlikely to negate the prevention benefit completely.

INTERPRETATION

PrEP could prevent a large number of new HIV infections if other key strategies including HIV testing and treatment are simultaneously expanded and improved. Without PrEP, HIV incidence in MSM in the UK is unlikely to decrease substantially by the end of this decade.

FUNDING

Health Protection Agency (now Public Health England).

Parameterising User Uptake in Economic Evaluations: The role of discrete choice experiments

Model-based economic evaluations of new interventions have shown that user behaviour (uptake) is a critical driver of overall impact achieved. However, early economic evaluations, prior to introduction, often rely on assumed levels of uptake based on expert opinion or uptake of similar interventions. In addition to the likely uncertainty surrounding these uptake assumptions, they also do not allow for uptake to be a function of product, intervention, or user characteristics. This letter proposes using uptake projections from discrete choice experiments (DCE) to better parameterize uptake and substitution in cost-effectiveness models. A simple impact model is developed and illustrated using an example from the HIV prevention field in South Africa. Comparison between the conventional approach and the DCE-based approach shows that, in our example, DCE-based impact predictions varied by up to 50% from conventional estimates and provided far more nuanced projections. In the absence of observed uptake data and to model the effect of variations in intervention characteristics, DCE-based uptake predictions are likely to greatly improve models parameterizing uptake solely based on expert opinion. This is particularly important for global and national level decision making around introducing new and probably more expensive interventions, particularly where resources are most constrained.

Sexual risk behaviour among people living with HIV according to the biomedical risk of transmission: results from the ANRS-VESPA2 survey

Introduction

People living with HIV (PLHIV) on antiretroviral therapy (ART), with sustained undetectable viral load (sUVL) and no history of sexually transmitted infections for at least six months, are considered to have a low risk of HIV transmission (LRT). We aimed to characterize, in a representative sample of French PLHIV, the sexual behaviour of LRT PLHIV compared with non-LRT PLHIV.

Methods

The cross-sectional ANRS-VESPA2 survey was conducted on adult PLHIV attending French hospitals in 2011. The LRT PLHIV group included participants with sUVL and no sexually transmitted infection for at least 12 months. Socio-behavioural and medical data were collected. Chi-square tests helped compare sexual risk indicators between LRT and non-LRT PLHIV. The survey's retrospective nature allowed us to perform complementary category-based analyses of LRT PLHIV according to whether they had sUVL for at least 18, 24 or 36 months in three socio-epidemiological groups: men who have sex with men (MSM), other men and women.

Results

Analysis included 2638 PLHIV diagnosed >12 months with available viral load data. The proportion of LRT PLHIV varied from 58% (≥12 months sUVL) to 38% (≥36 months sUVL). Irrespective of sUVL duration, we found the following: 1) LRT men (MSM and other men) were more likely to report having no sexual partner than their non-LRT counterparts. Among men having sexual partners in the previous 12 months, no significant difference was seen between LRT and non-LRT men in the number of sexual partners. LRT women were less likely to report having more than one sexual partner than non-LRT women; 2) LRT MSM were more likely to report being in sexually inactive couples than their non-LRT counterparts; 3) among sexually active participants, no difference was observed between LRT and non-LRT PLHIV concerning condom use with their serodiscordant steady partner or with their most recent casual sexual partners.

Conclusions

LRT PLHIV with sUVL ≥12 months did not report more sexual risk behaviours than their non-LRT counterparts. Because the same result was obtained for those having a sUVL ≥36 months, the hypothesis of increased sexual risk behaviour over time in PLHIV meeting non-transmission biomedical criteria is not supported.

How Stigma Surrounding the Use of HIV Preexposure Prophylaxis Undermines Prevention and Pleasure: A Call to Destigmatize "Truvada Whores"

Antiretroviral preexposure prophylaxis (PrEP; emtricitabine and tenofovir disoproxil fumarate [Truvada]) prevents HIV without penalizing sexual pleasure, and may even enhance pleasure (e.g., by reducing HIV-related anxiety). However, concern about sexual risk behavior increasing with PrEP use (risk compensation) and corresponding stereotypes of promiscuity may undermine PrEP's preventive potential. In this commentary, we review literature on sexual behavior change accompanying PrEP use, discuss risk compensation concerns and the "Truvada whore" stereotype as PrEP barriers, question the appropriateness of restricting PrEP access because of risk compensation, and consider sexual pleasure as a benefit of PrEP, an acceptable motive for seeking PrEP, and a core element of health. It is essential for science to trump stereotypes and sex-negative messaging in guiding decision-making affecting PrEP access and uptake.

Male circumcision for protection against HIV infection in sub-Saharan Africa: the evidence in favour justifies the implementation now in progress

This article responds to a recent 'controversy study' in Global Public Health by de Camargo et al. directed at three randomised controlled trials (RCTs) of male circumcision (MC) for HIV prevention. These trials were conducted in three countries in sub-Saharan Africa (SSA) and published in 2005 and 2007. The RCTs confirmed observational data that had accumulated over the preceding two decades showing that MC reduces by 60% the risk of HIV infection in heterosexual men. Based on the RCT results, MC was adopted by global and national HIV policy-makers as an additional intervention for HIV prevention. Voluntary medical MC (VMMC) is now being implemented in 14 SSA countries. Thus referring to MC for HIV prevention as 'debate' and viewing MC through a lens of controversy seems mistaken. In their criticism, de Camargo et al. misrepresent and misinterpret current science supporting MC for HIV prevention, omit previous denunciations of arguments similar to theirs, and ignore evidence from ongoing scientific research. Here we point out the flaws in three areas de Camargo et al. find contentious. In doing so, we direct readers to growing evidence of MC as an efficacious, safe, acceptable, relatively low-cost one-off biomedical intervention for HIV prevention.

Pre-exposure prophylaxis for human immunodeficiency virus: the past, present, and future

This article presents an overview of pre-exposure prophylaxis (PrEP) for human immunodeficiency virus (HIV) prevention. The authors describe the past animal and human research that has been conducted that informs our current understanding of PrEP; summarize ongoing research in the area, including describing new regimens and delivery mechanisms being studied for PrEP; and highlight key issues that must be addressed in order to implement and optimize the use of this HIV prevention tool.

Oral pre-exposure prophylaxis (PrEP) for prevention of HIV in serodiscordant heterosexual couples in the United States: opportunities and challenges

Oral HIV pre-exposure prophylaxis (PrEP) is a promising new biomedical prevention approach in which HIV-negative individuals are provided with daily oral antiretroviral medication for the primary prevention of HIV-1. Several clinical trials have demonstrated efficacy of oral PrEP for HIV prevention among groups at high risk for HIV, with adherence closely associated with level of risk reduction. In the United States (US), three groups have been prioritized for initial implementation of PrEP-injection drug users, men who have sex with men at substantial risk for HIV, and HIV-negative partners within serodiscordant heterosexual couples. Numerous demonstration projects involving PrEP implementation among MSM are underway, but relatively little research has been devoted to study PrEP implementation in HIV-serodiscordant heterosexual couples in the US. Such couples face a unique set of challenges to PrEP implementation at the individual, couple, and provider level with regard to PrEP uptake and maintenance, adherence, safety and toxicity, clinical monitoring, and sexual risk behavior. Oral PrEP also provides new opportunities for serodiscordant couples and healthcare providers for primary prevention and reproductive health. This article provides a review of the critical issues, challenges, and opportunities involved in the implementation of oral PrEP among HIV-serodiscordant heterosexual couples in the US.

Uptake of pre-exposure prophylaxis, sexual practices, and HIV incidence in men and transgender women who have sex with men: a cohort study

BACKGROUND

The effect of HIV pre-exposure prophylaxis (PrEP) depends on uptake, adherence, and sexual practices. We aimed to assess these factors in a cohort of HIV-negative people at risk of infection.

METHODS

In our cohort study, men and transgender women who have sex with men previously enrolled in PrEP trials (ATN 082, iPrEx, and US Safety Study) were enrolled in a 72 week open-label extension. We measured drug concentrations in plasma and dried blood spots in seroconverters and a random sample of seronegative participants. We assessed PrEP uptake, adherence, sexual practices, and HIV incidence. Statistical methods included Poisson models, comparison of proportions, and generalised estimating equations.

FINDINGS

We enrolled 1603 HIV-negative people, of whom 1225 (76%) received PrEP. Uptake was higher among those reporting condomless receptive anal intercourse (416/519 [81%] vs 809/1084 [75%], p=0·003) and having serological evidence of herpes (612/791 [77%] vs 613/812 [75%] p=0·03). Of those receiving PrEP, HIV incidence was 1·8 infections per 100 person-years, compared with 2·6 infections per 100 person-years in those who concurrently did not choose PrEP (HR 0·51, 95% CI 0·26-1·01, adjusted for sexual behaviours), and 3·9 infections per 100 person-years in the placebo group of the previous randomised phase (HR 0·49, 95% CI 0·31-0·77). Among those receiving PrEP, HIV incidence was 4·7 infections per 100 person-years if drug was not detected in dried blood spots, 2·3 infections per 100 person-years if drug concentrations suggested use of fewer than two tablets per week, 0·6 per 100 person-years for use of two to three tablets per week, and 0·0 per 100 person-years for use of four or more tablets per week (p<0·0001). PrEP drug concentrations were higher among people of older age, with more schooling, who reported non-condom receptive anal intercourse, who had more sexual partners, and who had a history of syphilis or herpes.

INTERPRETATION

PrEP uptake was high when made available free of charge by experienced providers. The effect of PrEP is increased by greater uptake and adherence during periods of higher risk. Drug concentrations in dried blood spots are strongly correlated with protective benefit.

FUNDING

US National Institutes of Health.

A scoping study to identify opportunities to advance the ethical implementation and scale-up of HIV treatment as prevention: priorities for empirical research

BACKGROUND

Despite the evidence showing the promise of HIV treatment as prevention (TasP) in reducing HIV incidence, a variety of ethical questions surrounding the implementation and "scaling up" of TasP have been articulated by a variety of stakeholders including scientists, community activists and government officials. Given the high profile and potential promise of TasP in combatting the global HIV epidemic, an explicit and transparent research priority-setting process is critical to inform ongoing ethical discussions pertaining to TasP.

METHODS

We drew on the Arksey and O'Malley framework for conducting scoping review studies as well as systematic approaches to identifying empirical and theoretical gaps within ethical discussions pertaining to population-level intervention implementation and scale up. We searched the health science database PubMed to identify relevant peer-reviewed articles on ethical and implementation issues pertaining to TasP. We included English language articles that were published after 2009 (i.e., after the emergence of causal evidence within this field) by using search terms related to TasP. Given the tendency for much of the criticism and support of TasP to occur outside the peer-reviewed literature, we also included grey literature in order to provide a more exhaustive representation of how the ethical discussions pertaining to TasP have and are currently taking place. To identify the grey literature, we systematically searched a set of search engines, databases, and related webpages for keywords pertaining to TasP.

RESULTS

Three dominant themes emerged in our analysis with respect to the ethical questions pertaining to TasP implementation and scale-up: (a) balancing individual- and population-level interests; (b) power relations within clinical practice and competing resource demands within health care systems; (c) effectiveness considerations and socio-structural contexts of HIV treatment experiences within broader implementation contexts.

CONCLUSION

Ongoing research and normative deliberation is required in order to successfully and ethically scale-up TasP within the continuum of HIV care models. Based on the results of this scoping review, we identify several ethical and implementation dimensions that hold promise for informing the process of scaling up TasP and that could benefit from new research.

The impact of patient race on clinical decisions related to prescribing HIV pre-exposure prophylaxis (PrEP): assumptions about sexual risk compensation and implications for access

Antiretroviral pre-exposure prophylaxis (PrEP) has received increasing recognition as a viable prescription-based intervention for people at risk for HIV acquisition. However, little is known about racial biases affecting healthcare providers' willingness to prescribe PrEP. This investigation sought to explore medical students' stereotypes about sexual risk compensation among Black versus White men who have sex with men seeking PrEP, and the impact of such stereotypes on willingness to prescribe PrEP. An online survey presented participants (n = 102) with a clinical vignette of a PrEP-seeking, HIV-negative man with an HIV-positive male partner. Patient race was systematically manipulated. Participants reported predictions about patient sexual risk compensation, willingness to prescribe PrEP, and other clinical judgments. Bootstrapping analyses revealed that the Black patient was rated as more likely than the White patient to engage in increased unprotected sex if prescribed PrEP, which, in turn, was associated with reduced willingness to prescribe PrEP to the patient.

Understanding partial protection and HIV risk and behavior following voluntary medical male circumcision rollout in Kenya

In the midst of scaling up voluntary medical male circumcision (VMMC) in Kenya, there is concern that men do not adequately understand that circumcision provides only partial protection against HIV. The study goal was to determine men's understanding of partial protection, perceptions of HIV risk before and after VMMC and use of protective measures following VMMC. In-depth interviews with 44 men aged 18-39 years recently circumcised or planning to undergo VMMC were conducted in two urban and rural districts in Nyanza Province, Kenya. Participants described partial protection as the need to continue using other HIV protective measures such as condoms, with numbers such as a '60 percent protection' or 'not 100 percent protection', and described how circumcision reduces HIV transmission such as reduced penile bruising or bleeding. Most said their HIV risk before VMMC was high and that VMMC would reduce their risk moderately. Participants demonstrated good understanding of partial protection and there was little suggestion of risk compensation following VMMC.

How much demand for New HIV prevention technologies can we really expect? Results from a discrete choice experiment in South Africa

Background

For the first time in the history of HIV, new bio-medical interventions have been shown to be effective in preventing HIV transmission. For these new HIV prevention technologies (NPTs) to have an impact on the epidemic, they must be widely used. This study uses a discrete choice experiment (DCE) to: understand the relative strength of women’s preferences for product characteristics, understand the implications for substitution away from male condoms, and inform realistic modelling of their potential impact and cost-effectiveness.

Methods

A DCE was conducted among 1017 women in urban South Africa. Women were presented with choices between potential women’s NPTs (microbicides, diaphragm, female condom) and ‘what I did last time’ (use or not use a condom) with different HIV and pregnancy prevention effectiveness’ and prices. Choice probabilities are estimated using the nested logit model and used to predict uptake.

Results

In this high HIV prevalence setting, HIV prevention effectiveness is the main driver of uptake followed by pregnancy prevention effectiveness. For example a microbicide with poor effectiveness would have niche appeal at just 11% predicted uptake, while a highly effective microbicide (95% effective against HIV and pregnancy) would have far wider appeal (56% predicted uptake). Though women who reported not using condoms were more likely to choose the NPTs, at current very high rates of male condom use in South Africa (60%), about half of microbicide uptake is projected to be among those currently not using condoms.

Conclusions

Women are very interested in NPTs, especially if highly effective in preventing HIV and pregnancy. Women in greatest need were also most likely to switch to the new products. Where products are not yet available for distribution, proxy data, such as that generated by DCEs, can bring realism to overly optimistic uptake scenarios found in many current impact models.