Epidemiological impact and cost-effectiveness of providing long-acting pre-exposure prophylaxis to injectable contraceptive users for HIV prevention in South Africa: a modelling study

Preferences for Long-Acting PrEP Products Among Women and Girls: A Quantitative Survey and Discrete Choice Experiment in Eswatini, Kenya, and South Africa

While oral pre-exposure prophylaxis (PrEP) can substantially reduce HIV risk, there are important barriers to uptake and adherence. We explored preferences for long-acting injectable and implantable PrEP among women and girls in Eswatini, Kenya, and South Africa. We conducted an online quantitative survey and discrete choice experiment (DCE) among adolescent girls (15-17), young women (18-29), and adult women (30-49). Participants completed a survey about their demographics and behavior and a DCE with 5 attributes (format, insertion location, number of insertions, dual-protection, and palpability). We recruited 1236 respondents (Eswatini = 420; Kenya = 350; South Africa = 493) in May 2022. Most participants were sexually active (72%), nearly 29% of whom reported recently engaging in transactional sex. 46% had heard of oral PrEP, but of those, only 16% reported having ever used it. Product format and dual-protection were significant predictors of product choice. Relative to a 2-month injection, participants had 1.76 times the odds (95% CI 1.08-2.04) of choosing a 6-month injectable, and 1.70 the odds (95% CI 1.06-1.92) of choosing a 12-month removable implant. Compared to a single-indication product, respondents had 2.46 times the odds (95% CI 1.04-2.68) of preferring a product also protecting against pregnancy, and 2.81 the odds (95% CI 1.04-3.05) of choosing a product that also protected against STIs. Adolescent girls and women in these countries showed strong preferences for longer-acting PrEP product formats, as well as those offering dual-protection. Introduction of long-acting options could improve PrEP uptake and reduce HIV burdens in east and southern African settings.

Perceptions of Pre-exposure Prophylaxis (PrEP) for HIV prevention among men living with HIV in the context of reproductive goals in South Africa: a qualitative study

BACKGROUND

Pre-exposure Prophylaxis (PrEP) and Treatment as Prevention (TasP) are effective strategies to prevent HIV transmission within serodifferent couples. However, limited usage of PrEP, knowledge and interest has been amongst the barriers for men, alongside testing and treatment adherence. We explored the perceptions of PreP for HIV prevention with Men living with HIV (MWH) who have reproductive goals, to understand awareness and experiences related to PrEP use in the context of HIV prevention with their partners.

METHODS

We undertook a qualitative study with 25 MWH aged 18 to 65 between April and September 2021 in South Africa. Potential participants were screened for eligibility and scheduled to participate in telephonic interviews. Interviews were audio recorded, transcribed, translated and thematically analysed.

RESULTS

Themes were organized into opportunities and barriers that men with HIV articulate as important for using PrEP to meet individual, couple, and community reproductive goals. At the individual level, some men were willing to discuss PrEP with their partners to protect their partners and babies from acquiring HIV. Lack of knowledge about PrEP among men was a potential barrier to promoting PrEP among their female partners. At the couple level, PrEP use was seen as a way to strengthen relationships between partners, signifying care, trust, and protection and was seen as a tool to help serodifferent couples meet their reproductive goals safely. At the community level, PrEP was viewed as a tool to promote HIV testing and prevention efforts, especially among men, but participants emphasized the need for more education and awareness.

CONCLUSION

Despite PrEP implementation in South Africa, awareness of PrEP among men with HIV in rural areas remains low. Engaging MWH to support their partners in accessing PrEP could be an innovative strategy to promote HIV prevention. Additionally, providing men with comprehensive reproductive health information can empower them to make more informed decisions, adopt safer sexual practices, and challenge societal norms and stigmas around HIV.

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.

Out-of-pocket Expenses and Time Spent on Clinic Visits Among HIV Pre-exposure Prophylaxis Users and Other Clinic Attendees in Eswatini

User costs constitute a barrier to the uptake of HIV pre-exposure prophylaxis (PrEP), but their magnitude appears rarely assessed. In this prospective observational study, we assessed self-reported out-of-pocket expenses (OOPE) and time spent on clinic visits during a PrEP demonstration project in Eswatini. At six public primary care clinics, 240 PrEP users and other clinic attendees were interviewed after a clinic visit. Among the 79.2% of clinic attendees reporting any medical OOPE (e.g., expenses for consultations or drugs) and/or non-medical OOPE (e.g., expenses for transport, food, or phone use), the median total OOPE was $1.36 (IQR 0.91-1.96). Non-medical OOPE occurred mostly due to transport expenses. The median travel time for a clinic visit was 1.0 h (IQR 0.67-2.0). The median time spent in the clinic was 2.0 h (IQR 1.15-3.0). The median opportunity cost of a clinic visit was $7.54 (IQR 5.42-11) when valuing time spent on a clinic visit with Eswatini's per-capita gross domestic product. Our findings can guide measures to reduce the user costs of PrEP in Eswatini and other contexts in which oral PrEP is provided through health care facilities.

Long-acting injectable cabotegravir for PrEP: A game-changer in HIV prevention?

BACKGROUND

Long-acting injectable cabotegravir (CAB-LA) represents a new additional option for HIV prevention in people at substantial risk of HIV infection that may fill the gaps in pre-exposure prophylaxis (PrEP) uptake, adherence, and retention in users having difficulty with oral PrEP. Data from clinical trials demonstrated that CAB-LA was safe, highly effective, and well-accepted for HIV prevention. However, the occurrence of breakthrough HIV infections despite timely injections, HIV seroconversion timing and patterns, risk of selection and dissemination of resistance-associated mutations to integrase inhibitors, complexity of follow-up, logistical considerations, and its cost effectiveness compared with oral PrEP constitute significant issues for the integration of CAB-LA into clinical routine.

FINDINGS

These concerns need to be addressed before moving forward with large-scale implementation programmes. Pilot and implementation projects are required in the following areas: HIV testing algorithms, patient education, clinic procedures, protocols for switching and discontinuation, efficacy and safety in populations not included in clinical trials, and demedicalization processes. The development of models to increase the uptake of, adherence to, and persistence with and after CAB-LA injections will also be of paramount importance for success. Lessons learned from these projects will increase experience, staff expertise, and organizational and training capacities to support the roll-out of this new agent as part of HIV prevention programmes.

CONCLUSION

CAB-LA has not yet achieved its full potential in HIV prevention, and strong commitment from all stakeholders is required to push CAB-LA as a game-changer in HIV response.

Relative cost-effectiveness of long-acting injectable cabotegravir versus oral pre-exposure prophylaxis in South Africa based on the HPTN 083 and HPTN 084 trials: a modelled economic evaluation and threshold analysis

BACKGROUND

Long-acting injectable cabotegravir, a drug taken every 2 months, has been shown to be more effective at preventing HIV infection than daily oral tenofovir disoproxil fumarate and emtricitabine, but its cost-effectiveness in a high-prevalence setting is not known. We aimed to estimate the incremental cost-effectiveness of long-acting injectable cabotegravir compared with tenofovir disoproxil fumarate and emtricitabine in South Africa, using methods standard to government planning, and to determine the threshold price at which long-acting injectable cabotegravir is as cost-effective as tenofovir disoproxil fumarate and emtricitabine.

METHODS

In this modelled economic evaluation and threshold analysis, we updated a deterministic model of the South African HIV epidemic with data from the HPTN 083 and HPTN 084 trials to evaluate the effect of tenofovir disoproxil fumarate and emtricitabine and long-acting injectable cabotegravir provision to heterosexual adolescents and young women and men aged 15-24 years, female sex workers, and men who have sex with men. We estimated the average intervention cost, in 2021 US$, using ingredients-based costing, and modelled the cost-effectiveness of two coverage scenarios (medium or high, assuming higher uptake of long-acting injectable cabotegravir than tenofovir disoproxil fumarate and emtricitabine throughout) and, for long-acting injectable cabotegravir, two duration subscenarios (minimum: same pre-exposure prophylaxis duration as for tenofovir disoproxil fumarate and emtricitabine; maximum: longer duration than tenofovir disoproxil fumarate and emtricitabine) over 2022-41.

FINDINGS

Across long-acting injectable cabotegravir scenarios, 15-28% more new HIV infections were averted compared with the baseline scenario (current tenofovir disoproxil fumarate and emtricitabine roll-out). In scenarios with increased coverage with oral tenofovir disoproxil fumarate and emtricitabine, 4-8% more new HIV infections were averted compared with the baseline scenario. If long-acting injectable cabotegravir drug costs were equal to those of tenofovir disoproxil fumarate and emtricitabine for the same 2-month period, the incremental cost of long-acting injectable cabotegravir to the HIV programme was higher than that of tenofovir disoproxil fumarate and emtricitabine (5-10% vs 2-4%) due to higher assumed uptake of long-acting injectable cabotegravir. The cost per infection averted was $6053-6610 (tenofovir disoproxil fumarate and emtricitabine) and $4471-6785 (long-acting injectable cabotegravir). The cost per long-acting cabotegravir injection needed to be less than twice that of a 2-month supply of tenofovir disoproxil fumarate and emtricitabine to remain as cost-effective, with threshold prices ranging between $9·03 per injection (high coverage; maximum duration) and $14·47 per injection (medium coverage; minimum duration).

INTERPRETATION

Long-acting injectable cabotegravir could potentially substantially change HIV prevention. However, for its implementation to be financially feasible across low-income and middle-income countries with high HIV incidence, long-acting injectable cabotegravir must be reasonably priced.

FUNDING

United States Agency for International Development, The Bill & Melinda Gates Foundation.

HIV Pre-exposure Prophylaxis Implant Stated Preferences and Priorities: Results of a Discrete Choice Experiment Among Women and Adolescent Girls in Gauteng Province, South Africa

For adolescent girls (AG) and young women (YW), adherence barriers may limit the effectiveness of daily oral HIV pre-exposure prophylaxis (PrEP). Due to its low-burden and long-lasting product attributes, PrEP implants could remove some of the critical adherence barriers of oral PrEP products for individuals at risk of HIV. To explore stated preferences for a long-acting PrEP implant, we conducted a quantitative survey and discrete choice experiment with AG (ages 15-17), YW (18-34), and female sex workers (FSW; ≥ 18) in Gauteng Province, South Africa. We completed 600 quantitative surveys across the three subgroups of women. Respondents stated preference for an implant that provided longer HIV protection (24 months versus 6 months) and required a single insertion. They stated that they preferred a biodegradable implant that could be removed within 1 month of insertion. Respondents had no preference for a particular insertion location. Overall, 78% of respondents said they would be likely (33%) or very likely (45%) to use a PrEP implant were one available, with the majority (82%) stating preference for a product that would provide dual protection against HIV and unintended pregnancies. To reduce their risk of HIV, AG, YW, and FSW in our survey reported a strong willingness to use long-acting, highly-effective, dissolvable PrEP implants.