ARV-based HIV prevention for women - where we are in 2014

Adaptation and validation of simple tools to screen and monitor for oral PrEP adherence

INTRODUCTION

Oral, vaginal and other pre-exposure prophylaxis (PrEP) products for HIV prevention are in various stages of development. Low adherence poses a serious challenge to successful evaluation in trials. In a previous study, we developed tools to screen for general adherence and specifically monitor intravaginal ring adherence within the context of HIV prevention clinical trials. This study aimed to further validate the screening tool and to adapt and provide initial psychometric validation for an oral pill monitoring tool.

MATERIALS AND METHODS

We administered a cross-sectional survey between June and October 2018 at a trial site located near Cape Town, South Africa, and another in Thika, Kenya, with 193 women who had experience using daily oral pills. We fit confirmatory factor analysis models on the screening tool items to assess our previously-hypothesized subscale structure. We conducted an exploratory factor analysis of oral PrEP monitoring items to determine the underlying subscale structure. We then assessed the construct validity of each tool by comparing subscales against each other within the current sample and against our original sample, from a study conducted in four sites in South Africa, including Cape Town.

RESULTS

The screening tool structure showed moderate evidence of construct validity. As a whole, the tool performed in a similar way to the original sample. The monitoring tool items, which were revised to assess perceptions about and experiences using daily oral PrEP, factored into five subscales that showed moderate to good reliability. Four of the five subscales had a similar structure overall to the vaginal ring monitoring tool from which they were adapted.

CONCLUSIONS

Accurate measurement of HIV-prevention product adherence is of critical importance to the assessment of product efficacy and safety in clinical trials, and the support of safe and effective product use in non-trial settings. In this study, we provide further validation for these measures, demonstrating the screening tool's utility in additional populations and adapting the monitoring tool's utility for different HIV-prevention products.

The impact of socioeconomic factors on the healthcare costs of people living with HIV in Turkey

Background

This study addresses an important field within HIV research, the impact of socioeconomic factors on the healthcare costs of people living with HIV/AIDS (PLHIV). We aimed to understand how different socioeconomic factors could create diverse healthcare costs for PLHIV in Turkey.

Methods

Data were collected between January 2017 and December 2017. HIV-positive people attending the clinic who had been referred to the national ART programme from January 1992 until December 2017 were surveyed. The questionnaire collected socioeconomic data. The cost data for the same patients was taken from the electronic database Probel Hospital Information Management System (PHIMS) for the same period. The PHIMS data include costs for medication (highly active antiretroviral therapy or HAART), laboratory, pathology, radiology, polyclinic, examination and consultation, hospitalisation, surgery and intervention, blood and blood products, supplies and other costs. Data were analysed using STATA 14.2 to estimate the generalised linear model (GLM).

Results

The findings of our GLM indicate that age, gender, marital and parental status, time since diagnosis, employment, wealth status, illicit drug use and CD4 cell count are the factors significantly related to the healthcare cost of patients. We found that compared with people who have AIDS (CD4 cells < 200 cells/mm³), people who have a normal range of CD4 cells (≥ 500 cells/mm³) have $1046 less in expenditures on average. Compared to younger people (19–39 years), older people (≥ 55) have $1934 higher expenditures on average. Costs are $644 higher on average for married people and $401 higher on average for people who have children. Healthcare costs are $518 and $651 higher on average for patients who are addicted to drugs and who use psychiatric drug(s), respectively. Compared to people who were recently diagnosed with HIV, people who were diagnosed ≥10 years ago have $743 lower expenditures on average.

Conclusion

Our results suggest that in addition to immunological status, socioeconomic factors play a substantial role in the healthcare costs of PLHIV. The key factors influencing the healthcare costs of PLHIV are also critical for public policy makers, healthcare workers, health ministries and employment community programs.

Cognitive testing of an instrument to evaluate acceptability and use of pre-exposure prophylaxis products among women

Given the range of pre-exposure prophylaxis (PrEP) products currently being tested to prevent HIV in women, a standardized Acceptability and Use of PrEP Products Among Women Tool may facilitate comparisons of product acceptability and use across different geographies, trials, and users. We conducted three rounds of cognitive interviewing over 2 months in 2016, with 28 South African women who had experience participating in a range of PrEP product trials. The final instrument contained 41 items, including five new items that improved construct validity and 22 items modified for clarity. Changes were made due to unclear wording, difficulty answering, participant embarrassment, low response variability, and administrative formatting. Cognitive interviewing provided a means to address issues that would have inhibited this tool's ability to accurately collect data otherwise. This rapid, low-cost study provided valuable insight into participants' understanding of questions and demonstrated the utility of cognitive interviewing in international clinical trials.

Factors Affecting Pre-Exposure Prophylaxis Implementation for Women in the United States: A Systematic Review

Oral HIV pre-exposure prophylaxis (PrEP) is a highly effective pill that HIV-negative individuals can take once daily to prevent HIV infection. Although PrEP is a private, user-controlled method that empowers women to protect themselves without relying on a partner's behavior, women's PrEP use has been extremely low. We systematically reviewed the literature to identify and summarize factors that may be affecting PrEP implementation for women in the United States. We conducted a search of the Centers for Disease Control and Prevention HIV/AIDS Prevention Research Synthesis Project database (MEDLINE, EMBASE, and CINAHL) and PubMed to identify peer-reviewed studies published between January 2000 and April 2018 that reported U.S. women's or health care providers' PrEP knowledge or awareness, willingness to use or prescribe, attitudes, barriers and facilitators to use or prescription, or PrEP adherence and discontinuation influences. Thirty-nine studies (26 women, 13 providers) met the eligibility criteria. In these studies, 0%-33% of women had heard of PrEP. Between 51% and 97% of women were willing to try PrEP, and 60%-92% of providers were willing to prescribe PrEP to women. Implementation barriers included access, cost, stigma, and medical distrust. Three studies addressed adherence or discontinuation. PrEP knowledge is low among women and providers. However, women and providers generally have positive views when aware of PrEP, including a willingness to use or prescribe PrEP to women. Most of the implementation barriers highlighted in studies were social or structural factors (e.g., access). Additional studies are needed to address research gaps, including studies of PrEP adherence and discontinuation.

Multipurpose tenofovir disoproxil fumarate electrospun fibers for the prevention of HIV-1 and HSV-2 infections in vitro

Sexually transmitted infections affect hundreds of millions of people worldwide. Both human immunodeficiency virus (HIV-1 and -2) and herpes simplex virus-2 (HSV-2) remain incurable, urging the development of new prevention strategies. While current prophylactic technologies are dependent on strict user adherence to achieve efficacy, there is a dearth of delivery vehicles that provide discreet and convenient administration, combined with prolonged-delivery of active agents. To address these needs, we created electrospun fibers (EFs) comprised of FDA-approved polymers, poly(lactic-co-glycolic acid) (PLGA) and poly(DL-lactide-co-ε-caprolactone) (PLCL), to provide sustained-release and in vitro protection against HIV-1 and HSV-2. PLGA and PLCL EFs, incorporating the antiretroviral, tenofovir disoproxil fumarate (TDF), exhibited sustained-release for up to 4 weeks, and provided complete in vitro protection against HSV-2 and HIV-1 for 24h and 1 wk, respectively, based on the doses tested. In vitro cell culture and EpiVaginal tissue tests confirmed the safety of fibers in vaginal and cervical cells, highlighting the potential of PLGA and PLCL EFs as multipurpose next-generation drug delivery vehicles.

Indigenous HIV Prevention Beliefs and Practices Among Low-Earning Chinese Sex Workers as Context for Introducing Female Condoms and Other Novel Prevention Options

New interventions to reduce HIV and sexually transmitted infections (STI) among female sex workers are introduced into the context of women's existing prevention beliefs and practices. These indigenous practices affected implementation of our program to introduce female condoms to women in sex-work establishments in southern China. We used ethnographic field observations and in-depth interviews to document common prevention methods women reported using to protect themselves before and during intervention implementation. Individual, sex-work establishment, and other contextual factors, including sources of information and social and economic pressures to use or reject prevention options, shaped their perceptions and selection of these methods and affected adoption of female condoms as an additional tool. Efforts to improve uptake of effective prevention methods among low-income sex workers require attention to the context and spectrum of women's HIV/STI prevention practices when introducing innovations such as female condoms, microbicides, pre-exposure prophylaxis pills, and others, as they become available.

Tenofovir-based oral preexposure prophylaxis prevents HIV infection among women

PURPOSE OF REVIEW

Despite tremendous promise as a female-controlled HIV prevention strategy, implementation of preexposure prophylaxis (PrEP) among women has been limited, in part because of disparate efficacy results from randomized trials in this population. This review synthesizes existing evidence regarding PrEP efficacy for preventing HIV infection in women and considerations for delivering PrEP to women.

RECENT FINDINGS

In three efficacy trials, conducted among men and women, tenofovir-based oral PrEP reduced HIV acquisition in subgroups of women by 49-79% in intent-to-treat analyses, and by >85% when accounting for PrEP adherence. Two trials did not demonstrate an HIV prevention benefit from PrEP in women, but substantial evidence indicates those results were compromised by very low adherence to the study medication. Qualitative research has identified risk perception, stigma, and aspects of clinical trial participation as influencing adherence to study medication. Pharmacokinetic studies provide supporting evidence that PrEP offers HIV protection in women who are adherent to the medication.

SUMMARY

Tenofovir-based daily oral PrEP prevents HIV acquisition in women. Offering PrEP as an HIV prevention option for women at high risk of HIV acquisition is a public health imperative and opportunities to evaluate implementation strategies for PrEP for women are needed.

Prospects for a Globally Effective HIV-1 Vaccine

A globally effective vaccine strategy must cope with the broad genetic diversity of HIV and contend with multiple transmission modalities. Understanding correlates of protection and the role of diversity in limiting protective vaccines with those correlates is key. RV144 was the first HIV-1 vaccine trial to demonstrate efficacy against HIV-1 infection. A correlates analysis comparing vaccine-induced immune responses in vaccinated-infected and vaccinated-uninfected volunteers suggested that IgG specific for the V1V2 region of gp120 was associated with reduced risk of HIV-1 infection and that plasma Env IgA was directly correlated with infection risk. RV144 and recent non-human primate (NHP) challenge studies suggest that Env is essential and perhaps sufficient to induce protective antibody responses against mucosally acquired HIV-1. Whether RV144 immune correlates can apply to different HIV vaccines, to populations with different modes and intensity of transmission, or to divergent HIV-1 subtypes remains unknown. Newer prime-boost mosaic and conserved sequence immunization strategies aiming at inducing immune responses of greater breadth and depth as well as the development of immunogens inducing broadly neutralizing antibodies should be actively pursued. Efficacy trials are now planned in heterosexual populations in southern Africa and men who have sex with men in Thailand. Although NHP challenge studies may guide vaccine development, human efficacy trials remain key to answer the critical questions leading to the development of a global HIV-1 vaccine for licensure.

Prospects for a globally effective HIV-1 vaccine

A globally effective vaccine strategy must cope with the broad genetic diversity of HIV and contend with multiple transmission modalities. Understanding correlates of protection and the role of diversity in limiting protective vaccines with those correlates is key. RV144 was the first HIV-1 vaccine trial to demonstrate efficacy against HIV-1 infection. A correlates analysis compared vaccine-induced immune responses in vaccinated-infected and vaccinated-uninfected volunteers suggested that IgG specific for the V1V2 region of gp120 was associated with reduced risk of HIV-1 infection and that plasma Env IgA was directly correlated with infection risk. RV144 and recent NHP challenge studies suggest that Env is essential and perhaps sufficient to induce protective antibody responses against mucosally acquired HIV-1. Whether RV144 immune correlates can apply to different HIV vaccines, to populations with different modes and intensity of transmission, or to divergent HIV-1 subtypes remains unknown. Newer prime-boost mosaic and conserved sequence immunization strategies aiming at inducing immune responses of greater breadth and depth as well as the development of immunogens inducing broadly neutralizing antibodies should be actively pursued. Efficacy trials are now planned in heterosexual populations in southern Africa and MSM in Thailand. Although NHP challenge studies may guide vaccine development, human efficacy trials remain key to answer the critical questions leading to the development of a global HIV-1 vaccine for licensure.

New prospects for a preventive HIV-1 vaccine

The immune correlates of risk analysis and recent non-human primate (NHP) challenge studies have generated hypotheses that suggest HIV-1 envelope may be essential and, perhaps, sufficient to induce protective antibody responses against HIV-1 acquisition at the mucosal entry. New prime-boost mosaic and conserved-sequence, together with replicating vector immunisation strategies aiming at inducing immune responses or greater breadth, as well as the development of immunogens inducing broadly neutralising antibodies and mucosal responses, should be actively pursued and tested in humans. Whether the immune correlates of risk identified in RV144 can be extended to other vaccines, other populations, or different modes and intensity of transmission, and against increasing HIV-1 genetic diversity, remains to be demonstrated. Although NHP challenge studies may guide vaccine development, human efficacy trials remain key for answering the critical questions leading to the development of a global HIV-1 vaccine for licensure.

Women and ARV-based HIV prevention - challenges and opportunities

ARV-based HIV prevention methods available in pill, gel or ring formulations (broadly referred to as microbicides) offer the possibility of protection against HIV for women who find it difficult because they cannot ask their partners to use condoms or even refuse sex. Partial efficacy of ARV-based medications has been demonstrated in a number of clinical trials around the world among various populations, building the evidence that ARV-based technologies will contribute to reducing the AIDS epidemic worldwide. Disappointing results, however, from two trials in sub-Saharan Africa, where poor adherence contributed to study closure due to futility, have raised questions about whether women at the centre of the epidemic are able to effectively use products that require routine use. Also, there are fears by some of risk compensation by decreased condom use because of the availability of microbicides when only partial efficacy has been demonstrated in microbicide trials to date. Of note, sub-analyses of biologic measures of adherence in trials where this was possible have shown a strong correlation between good adherence and efficacy, reinforcing the necessity of good adherence. Research conducted in conjunction with clinical trials and post-trials in advance of possible rollout of ARV-based products have examined social and cultural factors, gender-related and otherwise, influencing adherence and other aspects of women's use of products. These include HIV stigma, women's perception of risk, partner and community influences and the differing needs of women in various stages of life and in different circumstances. It is the purpose of this supplement to give voice to the needs of women who can benefit from woman-initiated methods by presenting research results and commentary to contribute to the global conversation about optimizing women's experience with ARV-based prevention.