Seasonal PrEP for partners of migrant miners in southern Mozambique: a highly focused PrEP intervention

Health Economics Research on Non-surgical Biomedical HIV Prevention: Identifying Gaps and Proposing a Way Forward

BACKGROUND AND OBJECTIVE

Although HIV prevention science has advanced over the last four decades, evidence suggests that prevention technologies do not always reach their full potential. Critical health economics evidence at appropriate decision-making junctures, particularly early in the development process, could help identify and address potential barriers to the eventual uptake of future HIV prevention products. This paper aims to identify key evidence gaps and propose health economics research priorities for the field of HIV non-surgical biomedical prevention.

METHODS

We used a mixed-methods approach with three distinct components: (i) three systematic literature reviews (costs and cost effectiveness, HIV transmission modelling and quantitative preference elicitation) to understand health economics evidence and gaps in the peer-reviewed literature; (ii) an online survey with researchers working in this field to capture gaps in yet-to-be published research (recently completed, ongoing and future); and (iii) a stakeholder meeting with key global and national players in HIV prevention, including experts in product development, health economics research and policy uptake, to uncover further gaps, as well as to elicit views on priorities and recommendations based on (i) and (ii).

RESULTS

Gaps in the scope of available health economics evidence were identified. Little research has been carried out on certain key populations (e.g. transgender people and people who inject drugs) and other vulnerable groups (e.g. pregnant people and people who breastfeed). Research is also lacking on preferences of community actors who often influence or enable access to health services among priority populations. Oral pre-exposure prophylaxis, which has been rolled out in many settings, has been studied in depth. However, research on newer promising technologies, such as long-acting pre-exposure prophylaxis formulations, broadly neutralising antibodies and multipurpose prevention technologies, is lacking. Interventions focussing on reducing intravenous and vertical transmission are also understudied. A disproportionate amount of evidence on low- and middle-income countries comes from two countries (South Africa and Kenya); evidence from other countries in sub-Saharan Africa as well as other low- and middle-income countries is needed. Further, data are needed on non-facility-based service delivery modalities, integrated service delivery and ancillary services. Key methodological gaps were also identified. An emphasis on equity and representation of heterogeneous populations was lacking. Research rarely acknowledged the complex and dynamic use of prevention technologies over time. Greater efforts are needed to collect primary data, quantify uncertainty, systematically compare the full range of prevention options available, and validate pilot and modelling data once interventions are scaled up. Clarity on appropriate cost-effectiveness outcome measures and thresholds is also lacking. Lastly, research often fails to reflect policy-relevant questions and approaches.

CONCLUSIONS

Despite a large body of health economics evidence on non-surgical biomedical HIV prevention technologies, important gaps in the scope of evidence and methodology remain. To ensure that high-quality research influences key decision-making junctures and facilitates the delivery of prevention products in a way that maximises impact, we make five broad recommendations related to: improved study design, an increased focus on service delivery, greater community and stakeholder engagement, the fostering of an active network of partners across sectors and an enhanced application of research.

Implementation and resource needs for long-acting PrEP in low- and middle-income countries: a scoping review

INTRODUCTION

Several low- and middle-income countries (LMICs) are preparing to introduce long-acting pre-exposure prophylaxis (LAP). Amid multiple pre-exposure prophylaxis (PrEP) options and constrained funding, decision-makers could benefit from systematic implementation planning and aligned costs. We reviewed national costed implementation plans (CIPs) to describe relevant implementation inputs and activities (domains) for informing the costed rollout of LAP. We assessed how primary costing evidence aligned with those domains.

METHODS

We conducted a rapid review of CIPs for oral PrEP and family planning (FP) to develop a consensus of implementation domains, and a scoping review across nine electronic databases for publications on PrEP costing in LMICs between January 2010 and June 2022. We extracted cost data and assessed alignment with the implementation domains and the Global Health Costing Consortium principles.

RESULTS

We identified 15 implementation domains from four national PrEP plans and FP-CIP template; only six were in all sources. We included 66 full-text manuscripts, 10 reported LAP, 13 (20%) were primary cost studies-representing seven countries, and none of the 13 included LAP. The 13 primary cost studies included PrEP commodities (n = 12), human resources (n = 11), indirect costs (n = 11), other commodities (n = 10), demand creation (n = 9) and counselling (n = 9). Few studies costed integration into non-HIV services (n = 5), above site costs (n = 3), supply chains and logistics (n = 3) or policy and planning (n = 2), and none included the costs of target setting, health information system adaptations or implementation research. Cost units and outcomes were variable (e.g. average per person-year).

DISCUSSION

LAP planning will require updating HIV prevention policies, technical assistance for logistical and clinical support, expanding beyond HIV platforms, setting PrEP achievement targets overall and disaggregated by method, extensive supply chain and logistics planning and support, as well as updating health information systems to monitor multiple PrEP methods with different visit schedules. The 15 implementation domains were variable in reviewed studies. PrEP primary cost and budget data are necessary for new product introduction and should match implementation plans with financing.

CONCLUSIONS

As PrEP services expand to include LAP, decision-makers need a framework, tools and a process to support countries in planning the systematic rollout and costing for LAP.

Infectious Disease Modelling of HIV Prevention Interventions: A Systematic Review and Narrative Synthesis of Compartmental Models

BACKGROUND

The HIV epidemic remains a major public health problem. Critical to transmission control are HIV prevention strategies with new interventions continuing to be developed. Mathematical models are important for understanding the potential impact of these interventions and supporting policy decisions. This systematic review aims to answer the following question: when a new HIV prevention intervention is being considered or designed, what information regarding it is necessary to include in a compartmental model to provide useful insights to policy makers? The primary objective of this review is therefore to assess suitability of current compartmental HIV prevention models for informing policy development.

METHODS

Articles published in EMBASE, Medline, Econlit, and Global Health were screened. Included studies were identified using permutations of (i) HIV, (ii) pre-exposure prophylaxis (PrEP), circumcision (both voluntary male circumcision [VMMC] and early-infant male circumcision [EIMC]), and vaccination, and (iii) modelling. Data extraction focused on study design, model structure, and intervention incorporation into models. Article quality was assessed using the TRACE (TRAnsparent and Comprehensive Ecological modelling documentation) criteria for mathematical models.

RESULTS

Of 837 articles screened, 48 articles were included in the review, with 32 unique mathematical models identified. The substantial majority of studies included PrEP (83%), whilst fewer modelled circumcision (54%), and only a few focussed on vaccination (10%). Data evaluation, implementation verification, and model output corroboration were identified as areas of poorer model quality. Parameters commonly included in the mathematical models were intervention uptake and effectiveness, with additional intervention-specific common parameters identified. We identified key modelling gaps; critically, models insufficiently incorporate multiple interventions acting simultaneously. Additionally, population subgroups were generally poorly represented-with future models requiring improved incorporation of ethnicity and sexual risk group stratification-and many models contained inappropriate data in parameterisation which will affect output accuracy.

CONCLUSIONS

This review identified gaps in compartmental models to date and suggests areas of improvement for models focusing on new prevention interventions. Resolution of such gaps within future models will ensure greater robustness and transparency, and enable more accurate assessment of the impact that new interventions may have, thereby providing more meaningful guidance to policy makers.

Costs and Cost-Effectiveness of Biomedical, Non-Surgical HIV Prevention Interventions: A Systematic Literature Review

BACKGROUND

Considerable evidence on the costs and cost-effectiveness of biomedical, non-surgical interventions to prevent human immunodeficiency virus (HIV) transmission has been generated over the last decade. This study aims to synthesize findings and identify remaining knowledge gaps to suggest future research priorities.

METHODS

A systematic literature review was carried out in August 2020 using the MEDLINE, Embase, Global Health and EconLit databases to retrieve economic evaluations and costing studies of oral pre-exposure prophylaxis (PrEP), injectable long-acting PrEP, vaginal microbicide rings and gels, HIV vaccines and broadly neutralizing antibodies. Studies reporting costs from the provider or societal perspective were included in the analysis. Those reporting on behavioural methods of prevention, condoms and surgical approaches (voluntary medical male circumcision) were excluded. The quality of reporting of the included studies was assessed using published checklists.

RESULTS

We identified 3007 citations, of which 87 studies were retained. Most were set in low- and middle-income countries (LMICs; n = 53) and focused on the costs and/or cost-effectiveness of oral PrEP regimens (n = 70). Model-based economic evaluations were the most frequent study design; only two trial-based cost-effectiveness analyses and nine costing studies were found. Less than half of the studies provided practical details on how the intervention would be delivered by the health system, and only three of these, all in LMICs, explicitly focused on service integration and its implication for delivery costs. 'Real-world' programme delivery mechanisms and costs of intervention delivery were rarely considered. PrEP technologies were generally found to be cost-effective only when targeting high-risk subpopulations. Single-dose HIV vaccines are expected to be cost-effective for all groups despite substantial uncertainty around pricing.

CONCLUSIONS

A lack of primary, detailed and updated cost data, including above-service level costs, from a variety of settings makes it difficult to evaluate the cost-effectiveness of specific delivery modes at scale, or to evaluate strategies for services integration. Closing this evidence gap around real-world implementation is vital, not least because the strategies targeting high-risk groups that are recommended by PrEP models may incur substantially higher costs and be of limited practical feasibility in some settings.

Service delivery models that promote linkages to PrEP for adolescent girls and young women and men in sub-Saharan Africa: a scoping review

BACKGROUND

Pre-exposure prophylaxis (PrEP) is an emerging biomedical prevention intervention. Documenting PrEP service delivery models (SDMs) that promote linkage to and continuation of PrEP will inform guidelines and maximise roll-out.

OBJECTIVES

To synthesise and appraise the effectiveness and feasibility of PrEP SDMs designed to promote linkage to PrEP care among adolescent girls and young women (AGYW) and men in sub-Saharan Africa (SSA).

ELIGIBILITY CRITERIA

Primary quantitative and qualitative studies published in English and conducted in SSA were included. No restrictions on the date of publication were applied.

SOURCES OF EVIDENCE

Methodology outlined in the Joanna Briggs Institute reviewers' manual was followed. PubMed, Cochrane library, Scopus, Web of Science and online-conference abstract archives were searched.

CHARTING METHODS

Data on article, population, intervention characteristics and key outcomes was charted in REDCap.

RESULTS AND CONCLUSION

Of the 1204 identified records, 37 (met the inclusion criteria. Health facility-based integrated models of PrEP delivery with family planning, maternal and child health or sexual and reproductive services to AGYW resulted in PrEP initiation of 16%-90%. Community-based drop-in centres (66%) was the preferred PrEP outlet for AGYW compared with public clinics (25%) and private clinics (9%). Most men preferred community-based delivery models. Among individuals who initiated PrEP, 50% were men, 62% were <35 years old and 97% were tested at health fairs compared with home testing. Integrated antiretroviral therapy (ART)-PrEP delivery was favoured among serodiscordant couples with 82.9% of couples using PrEP or ART with no HIV seroconversions. PrEP initiation within healthcare facilities was increased by perceived client-friendly services and non-judgemental healthcare workers. Barriers to PrEP initiation included distance to travel to and time spent at health facilities and perceived community stigma. PrEP SDMs for AGYW and men need to be tailored to the needs and preferences for each group. Programme implementers should promote community-based SDMs to increase PrEP initiation among AGYW and men.

Adherence challenges with daily oral pre-exposure prophylaxis during pregnancy and the postpartum period in South African women: a cohort study

INTRODUCTION

Daily oral pre-exposure prophylaxis (PrEP) can reduce HIV acquisition. However, prevention effectiveness requires daily adherence prior to and during periods of sexual activity. Little is known about pharmacologic measures of PrEP adherence during pregnancy and postpartum and the factors related to optimal adherence during periods of sexual activity in this population.

METHODS

Between August 2019 and October 2021, we enrolled pregnant women without HIV at their first antenatal care visit followed-up through 12 months postpartum. Eligible women ≥16 years old received HIV prevention counselling and were offered oral PrEP (TDF-FTC). We quantified tenofovir-diphosphate (TFV-DP) in dried blood spots in women who reported taking PrEP in the past 30 days (at quarterly follow-up visits). We used regression models with generalized estimating equations to evaluate correlates of TFV-DP (any vs. none, and ≥2 vs. <2 doses/week), adjusting for maternal age and pregnancy status.

RESULTS AND DISCUSSION

In 382 women who started PrEP in pregnancy, returned for follow-up and reported PrEP use in the past 30 days, the median age was 27 years (interquartile range [IQR] = 23-32), and the median time on PrEP was 168 days (IQR = 84-252 days). Half of the samples had quantifiable TFV-DP at any time point (52%), declining from 67% of pregnant women 3 months post-initiation to 31% of postpartum women by 12 months. Overall, 72% had concentrations corresponding to <2 doses/week; 25% ≥2 doses/week; 3% 7 doses/week. Concentrations were lower in postpartum versus pregnancy (age-adjusted odds ratio [aOR] = 0.44; 95% confidence interval [CI] = 0.35-0.54). The correlation of self-reported adherence and TFV-DP ranged from -0.07 in pregnancy to 0.25 in postpartum women. Variables associated with having quantifiable TFV-DP included partner living with HIV/unknown serostatus (aOR = 1.50; 95% CI = 1.01-2.22), and reported frequency of sexual activity in the past month (aOR sex >5/month vs. no sex or <5 times/month = 2.11; 95% CI = 1.58-2.82) adjusting for age and pregnancy versus postpartum status. TFV-DP concentrations declined over follow-up time (aOR for 6 vs. 3 months = 0.49; 95% CI = 0.36-0.67).

CONCLUSIONS

Objectively measured adherence to PrEP was low overall and did not correlate with self-reported use. There is an urgent need for objective adherence measures to support clinical decision-making as well as adherence support interventions as part of PrEP services for pregnant and postpartum women at risk of HIV.

Predictors of migration in an HIV hyper-endemic rural South African community: evidence from a population-based cohort (2005-2017)

Globally, South Africa hosts the highest number of people living with HIV (PLHIV) and the unique legacy of internal labour migration continues to be a major driver of the regional epidemic, interrupting treatment-as-prevention efforts. The study examined levels, trends, and predictors of migration in rural KwaZulu-Natal Province, South Africa, using population-based surveillance data from 2005 through 2017. We followed 69 604 adult participants aged 15-49 years and recorded their migration events (i.e., out-migration from the surveillance area) in 423 038 person-years over 525 397 observations. Multiple failure Cox-regression models were used to measure the risk of migration by socio-demographic factors: age, sex, educational status, marital status, HIV, and community antiretroviral therapy (ART) coverage. Overall, 69% of the population cohort experienced at least one migration event during the follow-up period. The average incidence rate of migration was 9.96 events and 13.23 events per 100 person-years in women and men, respectively. Migration rates declined from 2005 to 2008 then peaked in 2012 for both women and men. Adjusting for other covariates, the risk of migration was 3.4-times higher among young women aged 20-24 years compared to those aged ≥ 40 years (adjusted Hazard Ratio [aHR] = 3.37, 95% Confidence Interval [CI]: 3:19-3.57), and 2.9-times higher among young men aged 20-24 years compared to those aged ≥ 40 years (aHR = 2.86, 95% CI:2.69-3.04). There was a 9% and 27% decrease in risk of migration among both women (aHR = 0.91, 95% CI: 0.83 - 0.99) and men (aHR = 0.73, 95% CI 0.66 - 0.82) respectively per every 1% increase in community ART coverage. Young unmarried women including those living with HIV, migrated at a magnitude similar to that of their male counterparts, and lowered as ART coverage increased over time, reflecting the role of improved HIV services across space in reducing out-migration. A deeper understanding of the characteristics of a migrating population provides critical information towards identifying and addressing gaps in the HIV prevention and care continuum in an era of high mobility.

Incremental costs of integrated PrEP provision and effective use counselling in community‐based platforms for adolescent girls and young women in South Africa: an observational study

Introduction

Adolescent girls and young women (AGYW) are a priority population for pre‐exposure prophylaxis (PrEP), a highly effective HIV prevention method. However, effective PrEP use among AGYW has been low. Interventions to support PrEP effective use may improve pill‐taking. Affordability of PrEP programs depends on their cost. We, therefore, evaluated the cost of community‐based PrEP with effective use counselling.

Methods

Cost data from a randomized controlled trial were used to evaluate the cost of PrEP provision with effective use counselling offered to AGYW through community‐based HIV testing platforms between November 2018 and November 2019. AGYW were randomized to receive (1) group‐based community health club effective use counselling, (2) individualized effective use counselling or (3) community‐based PrEP dispensary. Task shifting of effective use counselling from nurses to trained lay counsellors was implemented in groups 1 and 2. Personnel costs were estimated from time‐and‐motion observations and staff interviews. Expenditure and ingredients‐based approaches were used to estimate costs for medical and non‐medical supplies.

Results

In total, 603 AGYW initiated PrEP and accrued a total of 1280 months on PrEP. Average cost per person‐month on PrEP with group‐based community health club, individualized effective use counselling and community‐based PrEP dispensary under the Department of Health scenario were similar and high (USD $55.32, $55.65 and $55.46, respectively) due to low PrEP client volume observed in the clinical trial. Increasing client volume (scaled Department of Health scenario) reduced cost per‐person month estimates to USD $15.48, $26.40 and $13.99, respectively.

Conclusions

As designed, individualized effective use counselling increased the cost of standard‐of‐care PrEP delivery by 89%, group‐based community health effective use counselling increased the cost of standard‐of‐care PrEP delivery by 11%. These estimates can inform cost‐effectiveness and budget impact analysis for PrEP provision with effective use counselling services.

Qualitative accounts of PrEP discontinuation from the general population in Eswatini

People in receipt of pre-exposure prophylaxis (PrEP) for the prevention of HIV in Sub-Saharan Africa often discontinue taking the medication. We conducted 27 semi-structured interviews with men and women who had started PrEP but did not return to the clinic for a refill after a 1, 2 or 3-month period. These 'discontinuation' clients were enrolled in a PrEP demonstration project for the general population in nurse-led, public-sector, primary-care clinics in Eswatini. Reasons for discontinuation included changes to self-perceived HIV risk such as the end of pregnancy and absent partners. Others described PrEP as inaccessible when working away from home and many described difficulties relating to a daily pill regimen and managing side effects. Female clients described being prohibited from using PrEP by their partners and co-wives. From these results, we recommend that client-centred counselling stresses the prevention-effective adherence paradigm, which promotes PrEP use in risk periods that are identifiable and PrEP discontinuation when the risk period has finished. A national scale up of PrEP may mitigate problems accessing PrEP. Extended counselling and support could assist with adherence and the management of side effects. Education and support for partners and families of PrEP clients may also contribute to better PrEP continuation.

Effect of a storytelling intervention on the retention of serodiscordant couples in ART/PrEP services at antenatal clinic in Namacurra province in Zambézia, Mozambique

Background

Sub-Saharan Africa reported 550,000 new HIV infections among women in 2018. Pregnancy and the postpartum period are associated with an increased risk of HIV acquisition (adjusted risk ratio [RR]: 2.8 during pregnancy and 4.0 in postpartum period vs. non-pregnant or postpartum women, respectively). Acquisition of HIV during pregnancy and breastfeeding increases risk of mother to child transmission. We propose to test the impact of a peer-delivered oral storytelling intervention to increase retention in, and adherence to, pre-exposure prophylaxis (PrEP)/combination antiretroviral treatment (ART) among expectant couples.

Design

We propose a randomized controlled trial (RCT) (35 intervention and 35 control couples) at a health facility where 11% of expectant couples were in serodiscordant relationships in 2018. Couples randomized to the storytelling arm will be visited by a two community volunteers and who successfully adhered to PrEP/ART during a recent pregnancy. This expert couple will orate to participating couples three stories (at 1, 3 and 5 weeks after study enrollment) designed to empower, educate, and establish “ideal” interpersonal communication strategies within couples/families, and support adherence practices among participants. The primary outcome among HIV-uninfected women will be adherence to PrEP at 3 months.

Conclusions

PrEP among at-risk pregnant women must be implemented so that high levels of adherence and retention are achievable for them and their partners. We will test our storytelling intervention to identify an optimal strategy for PrEP education and family engagement in a region with high HIV prevalence. Our results will have an impact by effectively engaging serodiscordant couples in prevention/treatment during pregnancy and beyond.

"I Just Decided to Stop:" Understanding PrEP Discontinuation Among Individuals Initiating PrEP in HIV Care Centers in Kenya

BACKGROUND

Preexposure prophylaxis (PrEP) discontinuation rates in clinical trials and demonstration projects have been well characterized; however, little is known about discontinuation in routine public health settings in sub-Saharan Africa. Understanding discontinuation in nonstudy settings is important for establishing expectations for PrEP continuation in national programs and for facilitating effective PrEP scale-up.

METHODS

We conducted in-depth interviews with 46 individuals who had initiated PrEP at 25 HIV comprehensive care clinics (CCCs) in central and western Kenya and whose clinic records indicated they had discontinued.

RESULTS

Many of our study participants discontinued PrEP when their perceived risk decreased (eg, hiatus or end of a sexual relationship or partner known to be living with HIV became virally suppressed). Others reported discontinuation due to side effects, daily pill burden, preference for condoms, or their partner's insistence. Participant narratives frequently described facility level factors such as stigma-related discomforts with accessing PrEP at CCCs, inconvenient clinic location or operating hours, long wait times, and short refill dates as discouraging factors, suggesting actionable areas for improving PrEP access and continuation.

CONCLUSION

Clients frequently make intentional decisions to discontinue PrEP as they weigh different prevention options within the context of complex lives. Many clients will decide to discontinue PrEP when perceiving themselves to be at reduced risk and PrEP counseling must include provisions for addressing seasons of risk. PrEP will not be the right prevention method for everyone, or forever. Expanding PrEP access points and increasing sex-positive messaging may facilitate PrEP being a better option for many.

The impact of self-selection based on HIV risk on the cost-effectiveness of preexposure prophylaxis in South Africa

OBJECTIVES

We explored the impact and cost-effectiveness of preexposure prophylaxis (PrEP) provision to different populations in South Africa, with and without effective self-selection by individuals at highest risk of contracting HIV (through concurrent partnerships and/or commercial sex).

DESIGN AND METHODS

We used a previously developed HIV transmission model to analyse the epidemiological impact of PrEP provision to adolescents, young adults, pregnant women, female sex workers (FSWs) and (MSM), and data from South African PrEP programmes to estimate the cost and cost-effectiveness of PrEP (cost in 2019 USD per HIV infection averted over 20 years, 2019, 38). PrEP uptake followed data from early implementation sites, scaled-up linearly over 3 years, with target coverage set to 18% for adolescents, young adults and pregnant women, 30% for FSW and 54% for MSM.

RESULTS

The annual cost of PrEP provision ranges between $75 and $134 per person. PrEP provision adolescents and young adults, regardless of risk behaviour, will each avert 3.2--4.8% of HIV infections over 20 years; provision to high-risk individuals only has similar impact at lower total cost. The incremental cost per HIV infection averted is lower in high-risk vs. all-risk sub-populations within female adolescents ($507 vs. $4537), male adolescents ($2108 vs. $5637), young women ($1592 vs. $10 323) and young men ($2605 vs. $7715), becoming cost saving within 20 years for high-risk adolescents, young women, MSM and FSWs.

CONCLUSION

PrEP is an expensive prevention intervention but uptake by those at the highest risk of HIV infection will make it more cost-effective, and cost-saving after 14-18 years.

"I Do Try To Use Condoms, But…": Knowledge and Interest in PrEP Among Male Sex Workers in Mexico City

In Mexico City, male sex workers (MSWs) are up to 126 times more likely to be living with HIV than the general public. We conducted interviews with 23 MSWs in Mexico City to examine their subjective understandings about their sexual risk behaviors and explore opportunities about HIV pre-exposure prophylaxis (PrEP) as a prevention approach in this group. Despite knowledge about sexual HIV risks, most participants reported condomless anal sex with clients. There was very little prior knowledge about PrEP, but very high interest in using a daily pill for prevention. Several participants expected an increase in condomless anal sex if taking PrEP, because of monetary incentives from clients or a perceived increase in pleasure. Additionally, seasonal sex workers expressed interest in using PrEP only during months when they were performing sex work. PrEP implementation efforts through Mexico's healthcare system should recognize the varying needs and sexual risk behaviors of MSWs.

A modeling framework to inform preexposure prophylaxis initiation and retention scale-up in the context of 'Getting to Zero' initiatives

OBJECTIVE(S)

'Getting to Zero' (GTZ) initiatives aim to eliminate new HIV infections over a projected time frame. Increased preexposure prophylaxis (PrEP) uptake among populations with the highest HIV incidence, such as young Black MSM, is necessary to accomplish this aim. Agent-based network models (ABNMs) can help guide policymakers on strategies to increase PrEP uptake.

DESIGN

Effective PrEP implementation requires a model that incorporates the dynamics of interventions and dynamic feedbacks across multiple levels including virus, host, behavior, networks, and population. ABNMs are a powerful tool to incorporate these processes.

METHODS

An ABNM, designed for and parameterized using data for young Black MSM in Illinois, was used to compare the impact of PrEP initiation and retention interventions on HIV incidence after 10 years, consistent with GTZ timelines. Initiation interventions selected individuals in serodiscordant partnerships, or in critical sexual network positions, and compared with a controlled setting where PrEP initiators were randomly selected. Retention interventions increased the mean duration of PrEP use. A combination intervention modeled concurrent increases in PrEP initiation and retention.

RESULTS

Selecting HIV-negative individuals for PrEP initiation in serodiscordant partnerships resulted in the largest HIV incidence declines, relative to other interventions. For a given PrEP uptake level, distributing effort between increasing PrEP initiation and retention in combination was approximately as effective as increasing only one exclusively.

CONCLUSION

Simulation results indicate that expanded PrEP interventions alone may not accomplish GTZ goals within a decade, and integrated scale-up of PrEP, antiretroviral therapy, and other interventions might be necessary.

HIV control strategies for sex worker-client contact networks

Controlling the spread of HIV among hidden, high-risk populations such as survival sex workers and their clients is becoming increasingly important in the ongoing fight against HIV/AIDS. Several sociological and structural factors render general control strategies ineffective in these settings; instead, focused prevention, testing and treatment strategies which take into account the nature of survival sex work are required. Using a dynamic bipartite network model of sexual contacts, we investigate the optimal distribution of treatment and preventative resources among sex workers and their clients; specifically, we consider control strategies that randomly allocate antiretroviral therapy and pre-exposure prophylaxis within each subpopulation separately. Motivated by historical data from a South African mining community, three main asymmetries between sex workers and clients are considered in our model: relative population sizes, migration rates and partner distributions. We find that preventative interventions targeted at female sex workers are the lowest cost strategies for reducing HIV prevalence, since the sex workers form a smaller population and have, on average, more sexual contacts. However, the high migration rate among survival sex workers limits the extent to which prevalence can be reduced using this strategy. To achieve a further reduction in HIV prevalence, testing and treatment in the client population cannot be ignored.

The impact, cost and cost-effectiveness of oral pre-exposure prophylaxis in sub-Saharan Africa: a scoping review of modelling contributions and way forward

INTRODUCTION

Oral pre-exposure prophylaxis (PrEP) is a new form of HIV prevention being considered for inclusion in national prevention portfolios. Many mathematical modelling studies have been undertaken that speak to the impact, cost and cost-effectiveness of PrEP programmes. We assess the available evidence from mathematical modelling studies to inform programme planning and policy decision making for PrEP and further research directions.

METHODS

We conducted a scoping review of the published modelling literature. Articles published in English which modelled oral PrEP in sub-Saharan Africa, or non-specific settings with relevance to generalized HIV epidemic settings, were included. Data were extracted for the strategies of PrEP use modelled, and the impact, cost and cost-effectiveness of PrEP for each strategy. We define an algorithm to assess the quality and relevance of studies included, summarize the available evidence and identify the current gaps in modelling. Recommendations are generated for future modelling applications and data collection.

RESULTS AND DISCUSSION

We reviewed 1924 abstracts and included 44 studies spanning 2007 to 2017. Modelling has reported that PrEP can be a cost-effective addition to HIV prevention portfolios for some use cases, but also that it would not be cost-effective to fund PrEP before other prevention interventions are expanded. However, our assessment of the quality of the modelling indicates cost-effectiveness analyses failed to comply with standards of reporting for economic evaluations and the assessment of relevance highlighted that both key parameters and scenarios are now outdated. Current evidence gaps include modelling to inform service development using updated programmatic information and ex post modelling to evaluate and inform efficient deployment of resources in support of PrEP, especially among key populations, using direct evidence of cost, adherence and uptake patterns.

CONCLUSIONS

Updated modelling which more appropriately captures PrEP programme delivery, uses current intervention scenarios, and is parameterized with data from demonstration and implementation projects is needed in support of more conclusive findings and actionable recommendations for programmes and policy. Future analyses should address these issues, aligning with countries to support the needs of programme planners and decision makers for models to more directly inform programme planning and policy.

The role of costing in the introduction and scale-up of HIV pre-exposure prophylaxis: evidence from integrating PrEP into routine maternal and child health and family planning clinics in western Kenya

INTRODUCTION

Understanding the cost of strategies to reach and deliver pre-exposure prophylaxis (PrEP) to priority populations is essential to assess the cost-effectiveness and budget impact of HIV prevention programmes. Providing PrEP through maternal and child health and family planning clinics offers a promising strategy to reach women in high HIV burden settings. We estimated incremental costs and explored the cost drivers of integrating PrEP delivery into routine maternal and child health and family planning services in Kenya.

METHODS

We conducted a costing study from the provider perspective within the PrEP Implementation for Young Women and Adolescents programme in western Kenya. We identified all within- and above-facility activities supporting PrEP delivery and measured clinical service time using time-and-motion studies. We obtained input costs from programme budgets, expenditure records and staff interviews. We estimated changes in costs if creatinine testing were postponed from initiation to first follow-up visit and if PrEP were prioritized to clients at high HIV risk using a behavioural risk assessment tool. We also projected costs under Ministry of Health (MOH) implementation assuming MOH salaries and programme supervision. We estimated annual numbers of PrEP visits from programme data abstracted from 16 facilities between November 2017 and June 2018. We report the cost per client-month of PrEP dispensed in 2017 USD.

RESULTS

For an annual programme output of 24,005 screenings, 4198 PrEP initiations and 4427 follow-up visits, the average cost per client-month of PrEP dispensed in the study was $26.52. Personnel, drugs and laboratory tests comprised 43%, 25% and 14% of programme costs respectively. Postponing creatinine testing and prioritizing PrEP delivery to clients at high HIV risk reduced total programme costs by 8% and 14% respectively. In the MOH scenario assuming no changes in outputs, the projected cost per client-month of PrEP dispensed decreased to $16.54 and total programme costs decreased by 38%.

CONCLUSIONS

Incremental PrEP costs are sensitive to the service delivery strategy used to engage priority populations. Postponing creatinine testing and prioritizing PrEP delivery to clients at high HIV risk may reduce costs. Context-specific cost data are crucial to assess the cost-effectiveness and affordability of PrEP delivery models.

'This is mine, this is for me': preexposure prophylaxis as a source of resilience among women in Eswatini

OBJECTIVE

To understand the relationship between HIV preexposure prophylaxis (PrEP) and resilience among Emaswati women.

DESIGN

A qualitative study using semistructured in-depth interviews.

METHODS

We interviewed 24 women who recently initiated PrEP at one of six public-sector primary-care clinics participating in a government demonstration project for PrEP for the general population, as well as 30 PrEP stakeholders from HIV policy, implementation and donor sectors.

RESULTS

PrEP clients and stakeholders described an environment marked by high HIV risk. In this context, clients felt PrEP enhanced their resilience through feelings of protection, control over HIV acquisition, choice in relation to when to take PrEP, sexual pleasure and relief from the fear and consequences of HIV infection. Those in serodiscordant relationships described improved partner communication and a shared sense of responsibility for HIV prevention. Both PrEP clients and stakeholders asserted that PrEP marketing and communication should be Emaswati-led and community-owned.

CONCLUSION

PrEP helps women in Eswatini envision longer, healthier and more fulfilled lives. PrEP enhances resilience through several pathways, including self-efficacy, choice, control over HIV infection and relief from the fear of HIV infection. Social marketing and information campaigns should not only focus on PrEP as an HIV-prevention method but also emphasize how PrEP has expanded choice, enhanced control and facilitated sexual enjoyment among PrEP clients.

Cost-effectiveness of HIV Prevention Interventions in Sub-Saharan Africa: A Systematic Review

BACKGROUND

Sub-Saharan Africa carries the highest HIV burden globally. It is important to understand how interventions cost-effectively fit within guidelines and implementation plans, especially in low- and middle-income settings. We reviewed the evidence from economic evaluations of HIV prevention interventions in sub-Saharan Africa to help inform the allocation of limited resources.

METHODS

We searched PubMed, Web of Science, Econ-Lit, Embase, and African Index Medicus. We included studies published between January 2009 and December 2018 reporting cost-effectiveness estimates of HIV prevention interventions. We extracted health outcomes and cost-effectiveness ratios (CERs) and evaluated study quality using the CHEERS checklist.

FINDINGS

60 studies met the full inclusion criteria. Prevention of mother-to-child transmission interventions had the lowest median CERs ($1144/HIV infection averted and $191/DALY averted), while pre-exposure prophylaxis interventions had the highest ($13,267/HIA and $799/DALY averted). Structural interventions (partner notification, cash transfer programs) have similar CERs ($3576/HIA and $392/DALY averted) to male circumcision ($2965/HIA) and were more favourable to treatment-as-prevention interventions ($7903/HIA and $890/DALY averted). Most interventions showed increased cost-effectiveness when prioritizing specific target groups based on age and risk.

INTERPRETATION

The presented cost-effectiveness information can aid policy makers and other stakeholders as they develop guidelines and programming for HIV prevention plans in resource-constrained settings.

Temporal Fluctuations in Behavior, Perceived HIV Risk, and Willingness to Use Pre-Exposure Prophylaxis (PrEP)

Individual perceptions of HIV risk influence willingness to use pre-exposure prophylaxis (PrEP) for HIV prevention. Among men who have sex with men (MSM) and male sex workers (MSWs), temporal or episodic changes in risk behavior may influence perceived risk and PrEP acceptability over time. We investigated fluctuations in perceived HIV risk and PrEP acceptability, comparing MSWs against MSM who do not engage in sex work. We conducted 8 focus groups (n = 38) and 56 individual interviews among MSM and MSWs in Providence, RI. Perceived HIV risk shaped willingness to use PrEP among both MSWs and MSM who did not engage in sex work, and risk perceptions changed over time depending on behavior. For MSWs, perceived risk cycled according to patterns of substance use and sex work activity. These cycles yielded an "access-interest paradox": an inverse relationship between willingness to use and ability to access PrEP. MSM who did not engage in sex work also reported temporal shifts in risk behavior, perceived risk, and willingness to use PrEP, but changes were unrelated to access. MSM attributed fluctuations to seasonal changes, vacations, partnerships, behavioral "phases," and episodic alcohol or drug use. Efforts to implement PrEP among MSM and street-based MSWs should address temporal changes in willingness to use PrEP, which are linked to perceived risk. Among MSWs, confronting the access-interest paradox may require intensive outreach during high-risk times and efforts to address low perceived risk during times of reduced sex work.

Lessons from a decade of voluntary medical male circumcision implementation and their application to HIV pre-exposure prophylaxis scale up

Oral pre-exposure prophylaxis (PrEP) has the ability to curb HIV incidence worldwide and bring us closer to ending the HIV epidemic. Scale up of PrEP service delivery has many similar challenges to those faced by voluntary medical male circumcision (VMMC) services roll-out. This article outlines ten important lessons learned during the scale up of VMMC services in sub-Saharan Africa and their application to current oral PrEP implementation efforts to promote faster expansion for public health impact.

Partners-based HIV treatment for seroconcordant couples attending antenatal and postnatal care in rural Mozambique: A cluster randomized trial protocol

BACKGROUND

In resource-limited rural settings, scale-up of services to eliminate mother-to-child transmission of HIV has not been as effective as in better resourced urban settings. In sub-Saharan Africa, women often require male partner approval to access and remain engaged in HIV care. Our study will evaluate a promising male engagement intervention ("Homens para Saúde Mais" (HoPS+) [Men for Health Plus]) targeting the elimination of mother-to-child transmission in rural Mozambique.

DESIGN

We will use a cluster randomized clinical trial design to engage 24 health facilities (12 intervention and 12 standard of care), with 45 HIV-infected seroconcordant couples per clinic. The planned intervention will engage male partners to address social-structural and cultural factors influencing eMTCT based on new couple-centered integrated HIV services.

CONCLUSIONS

The HoPS+ study will evaluate the effectiveness of engaging male partners in antenatal care to improve outcomes among HIV-infected pregnant women, their HIV-infected male partners, and their newborn children. Our objectives are to: (1) Implement and evaluate the impact of male-engaged, couple-centered services on partners' retention in care, adherence to antiretroviral therapy, early infant diagnosis uptake, and mother-to-child transmission throughout pregnancy and breastfeeding; (2) Investigate the impact of HoPS+ intervention on hypothesized mechanisms of change; and (3) Use validated simulation models to evaluate the cost-effectiveness of the HoPS+ intervention with the use of routine clinical data from our trial. We expect the intervention to lead to strategies that can improve outcomes related to partners' retention in care, uptake of services for HIV-exposed infants, and reduced MTCT.

Cost and cost-effectiveness analysis of pre-exposure prophylaxis among men who have sex with men in two hospitals in Thailand

INTRODUCTION

In 2014, the Government of Thailand recommended pre-exposure prophylaxis (PrEP) as an additional HIV prevention programme within Thailand's National Guidelines on HIV/AIDS Treatment Prevention. However, to date implementation and uptake of PrEP programmes have been limited, and evidence on the costs and the epidemiological and economic impact is not available.

METHODS

We estimated the costs associated with PrEP provision among men having sex with men (MSM) participating in a facility-based, prospective observational cohort study: the Test, Treat and Prevent HIV Programme in Thailand. We created a suite of scenarios to estimate the cost-effectiveness of PrEP and sensitivity of the results to the model input parameters, including PrEP programme effectiveness, PrEP uptake among high-risk and low-risk MSM, baseline and future antiretroviral therapy (ART) coverage, condom use, unit cost of delivering PrEP, and the discount rate.

RESULTS

Drug costs accounted for 82.5% of the total cost of providing PrEP, followed by lab testing (8.2%) and personnel costs (7.8%). The estimated costs of providing the PrEP package in accordance with the national recommendation ranges from US$223 to US$311 per person per year. Based on our modelling results, we estimate that PrEP would be cost-effective when provided to either high-risk or all MSM. However, we found that the programme would be approximately 32% more cost-effective if offered to high-risk MSM than it would be if offered to all MSM, with an incremental cost-effectiveness ratio of US$4,836 per disability-adjusted life years (DALY) averted and US$7,089 per DALY averted respectively. Cost-effectiveness acceptability curves demonstrate that 80% of scenarios would be cost-effective when PrEP is provided solely to higher-risk MSM.

CONCLUSION

We provide the first estimates on cost and cost-effectiveness of PrEP in the Asia-Pacific region, and offer insights on how to deliver PrEP in combination with ART. While the high drug cost poses a budgeting challenge, incorporating PrEP delivery into an existing ART programme could be a cost-effective strategy to prevent HIV infections among MSM in Thailand.

Feasibility, Acceptability, and Adherence with Short-Term HIV Preexposure Prophylaxis in Female Sexual Partners of Migrant Miners in Mozambique

BACKGROUND

Preexposure prophylaxis (PrEP) offers protection from HIV acquisition if taken as prescribed. We evaluated the feasibility, acceptability, and adherence with short-term PrEP among female sexual partners of migrant miners in Mozambique.

METHODS

HIV-negative female sexual partners of migrant miners were offered daily tenofovir/emtricitabine (TDF/FTC) for 6 weeks concurrent with miners' return home. Study visits occurred at baseline, week 4, 6, and 8. Dried blood spots (DBSs) were collected at week 4 and 6.

RESULTS

Seventy-four women (median age: 42 years) were enrolled, 95% reported having 1 sexual partner and 80% reported never or rarely using condoms. At baseline, 41% had never tested for HIV; 65% were unaware of partners' HIV status. Of all women, 72 (97%) initiated PrEP, 7 (9%) discontinued PrEP before week 6; only 1 due to adverse events. Missed doses in the last week were self-reported by 8% and 3% of women at week 4 and 6, respectively. Of 66 (89%) women with DBS at week 4, 79% had detectable tenofovir diphosphate (TFV-DP) and 44% had levels consistent with ≥4 pills/wk (≥700 fmol/punch). Of 63 (88%) women with DBS at week 6, 76% had detectable TFV-DP and 42% had levels consistent with ≥4 pills/wk.

CONCLUSIONS

In this first study assessing the use of short-term PrEP, a high percent of female partners of migrant workers initiated PrEP and had detectable DP levels during follow-up. Further efforts are needed to enhance adherence to ensure protection from HIV acquisition. Short-term PrEP offers promise for populations who are at high risk of HIV during specific periods of time.

Willingness to use short-term oral pre-exposure prophylaxis (PrEP) by migrant miners and female partners of migrant miners in Mozambique

Migrant miners from Mozambique who work in South Africa and their partners are at substantial risk for HIV infection. We conducted a cross-sectional study to assess the willingness of migrant miners and female partners of miners to take short-term pre-exposure prophylaxis (PrEP) for prevention of HIV acquisition. The study was conducted in Gaza Province, Mozambique, between September and October 2015. A total of 131 male miners and female partners of male miners completed a questionnaire. Subsequently, 48 in-depth interviews among male miners and female partners of miners and 3 focus-group discussions (6 participants each) among female partners of miners were conducted. Quantitative data were tabulated using Stata. A structured coding scheme was developed and qualitative data were analysed using Atlas.ti. Most participants (94%) were willing to take PrEP for short-term use. Facilitating factors for willingness to use PrEP were concerns about partner's sexual behaviour, desire for pregnancy and one's own sexual behaviour. The main barriers to PrEP use were concerns regarding side-effects, perceived difficulty adhering to daily pill taking and concern about partner/family disapproval. Overall, participants saw potential barriers for PrEP as minor obstacles that could be overcome. The male partner's influence on PrEP use was significant.

Factors Associated with Use of Short-Term Pre-Exposure Prophylaxis for HIV Among Female Partners of Migrant Miners in Mozambique

Effective interventions tailored to specific types of behaviors and contexts are needed for women at risk for HIV acquisition. Oral pre-exposure prophylaxis (PrEP) is an efficacious HIV prevention intervention that uses antiretroviral drugs to reduce the risk of acquiring HIV infection. In Mozambique, HIV remains a major public health concern, with a national prevalence of 13%. Studies have demonstrated that the migration of male miners between southern provinces of Mozambique and South Africa is contributing to the HIV epidemic in Mozambique. This increased risk is associated with the engagement of male miners, while separated from their partners, in sexual relationships with other women, including transactional sex workers, in a hyperendemic setting in South Africa. We conducted 25 in-depth interviews with a subset of female partners in a stable relationship with migrant miners participating in a prospective cohort study to assess the feasibility, acceptability, and adherence to daily oral short-term PrEP. Drug levels were available for the participants, as reported in an earlier study. Interviews were recorded, transcribed, and submitted for qualitative thematic analysis. The major themes identified were the benefits of taking PrEP, the ease of taking daily PrEP, the reluctance to disclose PrEP use to partners, the lack of changes in sexual behavior, and prevailing gender dynamics and how they impact women's ability to access PrEP and other HIV prevention interventions.

Prevalence of sexually transmitted infections among Tanzanian migrants: a cross-sectional study

For the many millions of migrants, mobility creates vulnerabilities and elevates risk for sexually transmitted infections (STIs). We document, among Tanzanian agricultural plantation residents, migrant characteristics and test associations between migrant status and prevalent STI (HSV-2, syphilis, and HIV). From 623 plantation resident participants, we limit this analysis to participants about whom we know migration status (migrants n = 242, non-migrants n = 291). We collected behavioral data via audio-computer assisted self-interview survey, and clinical data via STI testing. We used multivariate Poisson regression models, stratified by gender and controlling for behavioral risk factors, to measure associations between migrant status and STI. In men, HIV prevalence was 9% for migrants, and 6% for non-migrants. HSV-2 prevalence was 57% for migrants, and 32% for non-migrants. Syphilis prevalence was 12% for migrants, and 3% for non-migrants. Among women, there were few differences in STI prevalence by migrant status: prevalence of HIV was 6% vs. 5% (migrants vs. non-migrants); HSV-2 prevalence was 68% vs. 65%; and syphilis prevalence was 11% vs. 8%. Being a male migrant was significantly associated with increased prevalence of any STI after controlling for sociodemographic and behavioral characteristics (APR = 1.53, 95% CI 1.23-5.25). Migrant women did not have increased prevalence of STI as compared to non-migrant women (APR = 1.03, 95% CI 0.85-1.24). Amongst Tanzanian agricultural workers, male migrants experienced elevated risk for prevalent STI as compared to male non-migrants. We suggest structural interventions to reduce risks associated with migration, especially in male migrants, including workplace-based STI prevention programs, and connecting migrants to resources and support within new communities. The key messages are: migrant men experience significantly elevated risk for prevalent STI, above and beyond sociodemographic and behavioral risk factors, as compared to their non-migrant peers; women in this Tanzanian agricultural plantation community overall had higher prevalence of some STIs than men, migrant women had similar STI risk as non-migrant women; and migration for work, an economic strategy for millions, also creates vulnerabilities, so workplace-based STI prevention programs and connecting migrants to community resources are essential.

Modeling and Cost-Effectiveness in HIV Prevention

With HIV funding plateauing and the number of people living with HIV increasing due to the rollout of life-saving antiretroviral therapy, policy makers are faced with increasingly tighter budgets to manage the ongoing HIV epidemic. Cost-effectiveness and modeling analyses can help determine which HIV interventions may be of best value. Incidence remains remarkably high in certain populations and countries, making prevention key to controlling the spread of HIV. This paper briefly reviews concepts in modeling and cost-effectiveness methodology and then examines results of recently published cost-effectiveness analyses on the following HIV prevention strategies: condoms and circumcision, behavioral- or community-based interventions, prevention of mother-to-child transmission, HIV testing, pre-exposure prophylaxis, and treatment as prevention. We find that the majority of published studies demonstrate cost-effectiveness; however, not all interventions are affordable. We urge continued research on combination strategies and methodologies that take into account willingness to pay and budgetary impact.

Psycho-social Correlates of Condom Use and HIV Testing among MSM Refugees in Beirut, Lebanon

MSM refugees have to deal with personal challenges and social/structural adversaries based on their refugee status on top of their sexual identity. To better customize interventions beside this population, we explored psycho-social and structural correlates of condom use and HIV testing in Lebanon by surveying and testing 150 participants. 67 % self-identified as gay. 84.6 % reported any unprotected anal intercourse (UAI) with men in the prior 3 months. Those who engaged in UAI, were lest comfortable with a doctor, didn't know where to get free HIV testing, experienced discrimination based on their refugee status and spent more time with their refugee peers, were less inclined to have seen a doctor in the past 12 month or knew where to get free HIV testing. Ever having been HIV tested was associated with being comfortable with medical doctors, knowing where to get HIV testing and spending time with other peer refugees. HIV prevention and testing promotion efforts targeting MSM refugees need to account for structural barriers, while fighting discrimination is crucial for a healthy sexual identity development.

HIV Prevalence and Demographic Determinants of Unprotected Anal Sex and HIV Testing among Male Refugees Who have Sex with Men in Beirut, Lebanon

Men who have sex with men (MSM), the same as refugees are at higher risk for health issues including HIV infection. With the large influx of refugees to Lebanon, and to better understand HIV transmission in this setting, we explored the socio-demographic correlates of condom use and HIV testing among MSM refugees in Beirut, by surveying and testing 150 participants. 67 % self-identified as gay, 84.6 % of respondents reported unprotected anal intercourse (UAI) in the prior 3 months, and 56.7 % with men of positive or unknown HIV status (UAIPU). 2.7 % tested positive for HIV, and 36 % reported having engaged in sex work. Men in a relationship and men who self-identified as gay had higher odds of UAI, of ever been tested, but lower odds of UAIPU. HIV prevention and testing promotion efforts targeting MSM refugees need to account for how men self-identify in relation to their sexual behavior and relationship status. Such efforts also should place emphasis on MSM of lower socio-economic status.

PrEP implementation: moving from trials to policy and practice

Introduction

It is increasingly clear that the HIV response will not be sustainable if the number of infections is not significantly reduced.

Discussion

For two decades, research has been ongoing to identify new behavioural and biomedical strategies to prevent HIV infection. In the past few years, the efficacy of several new strategies has been demonstrated, including oral pre-exposure prophylaxis (PrEP; i.e. daily use of tenofovir/emtricitabine). Because several social, political and logistic barriers remain, however, optimal PrEP implementation will require a better dissemination of new evidence in a number of areas and additional implementation research from various disciplinary perspectives (i.e. social science, policy and ethics; health systems; and economics, including cost-effectiveness studies). Discussion of new evidence on those topics, as well as case studies of potential PrEP implementation in diverse environments, can improve the understanding of the role that PrEP may play in addressing the global HIV/AIDS epidemic.

In light of these needs, the Network for Multidisciplinary Studies in ARV-based HIV Prevention (NEMUS) and the World Health Organization (WHO) were honoured to co-organize a special issue of JIAS aimed at contributing to a scholarly discussion of current conditions surrounding PrEP implementation, potential impact and efficiency, social science concerns and the study of PrEP implementation in specific country cases. The papers included in this monograph identify and cover many of the main aspects of the complex yet promising discussions around PrEP implementation today.

Conclusions

This is a collection of timely contributions from global leaders in HIV research and policy that addresses geographic diversity, uses a trans-disciplinary approach and covers a variety of the complex issues raised by PrEP. As this publication will become accessible to all, we hope that it will remain a valuable resource for policy makers, programme managers, researchers and activists around the world at a moment of a paradigm shift of the global response to HIV.