Characteristics of Women Enrolled into a Randomized Clinical Trial of Dapivirine Vaginal Ring for HIV-1 Prevention

Current insights and molecular docking studies of HIV-1 reverse transcriptase inhibitors

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS), a lethal disease that is prevalent worldwide. According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) data, 38.4 million people worldwide were living with HIV in 2021. Viral reverse transcriptase (RT) is an excellent target for drug intervention. Nucleoside reverse transcriptase inhibitors (NRTIs) were the first class of approved antiretroviral drugs. Later, a new type of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were approved as anti-HIV drugs. Zidovudine, didanosine, and stavudine are FDA-approved NRTIs, while nevirapine, efavirenz, and delavirdine are FDA-approved NNRTIs. Several agents are in clinical trials, including apricitabine, racivir, elvucitabine, doravirine, dapivirine, and elsulfavirine. This review addresses HIV-1 structure, replication cycle, reverse transcription, and HIV drug targets. This study focuses on NRTIs and NNRTIs, their binding sites, mechanisms of action, FDA-approved drugs and drugs in clinical trials, their resistance and adverse effects, their molecular docking studies, and highly active antiretroviral therapy (HAART).

The Association Between Heterosexual anal Intercourse and HIV Acquisition in Three Prospective Cohorts of Women

The extent to which receptive anal intercourse (RAI) increases the HIV acquisition risk of women compared to receptive vaginal intercourse (RVI) is poorly understood. We evaluated RAI practice over time and its association with HIV incidence during three prospective HIV cohorts of women: RV217, MTN-003 (VOICE), and HVTN 907. At baseline, 16% (RV 217), 18% (VOICE) of women reported RAI in the past 3 months and 27% (HVTN 907) in the past 6 months, with RAI declining during follow-up by around 3-fold. HIV incidence in the three cohorts was positively associated with reporting RAI at baseline, albeit not always significantly. The adjusted hazard rate ratios for potential confounders (aHR) were 1.1 (95% Confidence interval: 0.8-1.5) for VOICE and 3.3 (1.6-6.8) for RV 217, whereas the ratio of cumulative HIV incidence by RAI practice was 1.9 (0.6-6.0) for HVTN 907. For VOICE, the estimated magnitude of association increased slightly when using a time-varying RAI exposure definition (aHR = 1.2; 0.9-1.6), and for women reporting RAI at every follow-up survey (aHR = 2.0 (1.3-3.1)), though not for women reporting higher RAI frequency (> 30% acts being RAI vs. no RAI in the past 3 months; aHR = 0.7 (0.4-1.1)). Findings indicated precise estimation of the RAI/HIV association, following multiple RVI/RAI exposures, is sensitive to RAI exposure definition, which remain imperfectly measured. Information on RAI practices, RAI/RVI frequency, and condom use should be more systematically and precisely recorded and reported in studies looking at sexual behaviors and HIV seroconversions; standardized measures would aid comparability across geographies and over time.

Correlates of Adherence to the Dapivirine Vaginal Ring for HIV-1 Prevention

Understanding characteristics associated with adherence to pre-exposure prophylaxis (PrEP) methods for HIV-1 prevention may assist with optimizing implementation efforts. The dapivirine vaginal ring is a novel topical PrEP delivery method. Using data from a randomized, double-blind, placebo-controlled, phase III trial of the dapivirine vaginal ring conducted in four African countries, generalized estimating equation models were used to evaluate correlates of ring adherence. Two levels of quarterly dapivirine blood plasma, and dapivirine released from returned rings defined measures of adherence for recent and cumulative use, respectively. Time on study, calendar time, primary partner knowledge that the participant was taking part in the study, and use of long-acting contraceptive methods were associated with ring adherence whereas younger age, ring worries, condom use, episodes of menstrual bleeding and vaginal washing were associated with non-adherence. These findings may be useful for recruitment into future clinical studies and dapivirine ring implementation efforts.

Greater dapivirine release from the dapivirine vaginal ring is correlated with lower risk of HIV-1 acquisition: a secondary analysis from a randomized, placebo-controlled trial

INTRODUCTION

A vaginal ring containing 25 mg of the antiretroviral dapivirine has demonstrated efficacy in reducing women's risk of sexually acquiring HIV-1; however, imperfect ring use likely diluted efficacy estimates in clinical trials. The amount of dapivirine remaining in returned rings may reflect the extent of product use, permitting estimation of HIV protection in the context of consistent use.

METHODS

We measured the amount of dapivirine in returned rings from a placebo-controlled trial of the dapivirine vaginal ring conducted between August 2012 and June 2015 among 2629 African women. Phase I/II studies established that greater than 4 mg of dapivirine on average is released from the ring when used consistently over 28 days and ≤0.9 mg released suggested non-use. We assessed the relative risk reduction associated with levels of ring use using residual dapivirine in returned rings as a time-dependent covariate for HIV-1 infection in multivariable Cox models, including multiple exploratory analyses designed to estimate upper limits of efficacy given uncertainty in timing of HIV-1 acquisition. All models were adjusted for baseline covariates associated with HIV risk and adherence.

RESULTS

Residual dapivirine levels indicating at least some use (>0.9 mg released over a month) were associated with a 48% relative reduction in HIV-1 acquisition risk (95% confidence interval (CI): 21% to 66%; p = 0.002) compared to the placebo. Exploratory analyses accounting for potential misclassification in timing of HIV-1 acquisition estimated 75% to 91% HIV-1 risk reduction with> 4 mg released when compared to placebo. Results limited to the subgroup of women <25 years of age, who tended to have lower adherence, were generally consistent to those overall.

CONCLUSIONS

Residual dapivirine levels, an objective measure of adherence, were correlated with HIV-1 protection in a secondary analysis of a randomized trial. Periods of ring use were associated with approximately 50% protection, with exploratory analyses suggesting higher protection with more consistent use. The dapivirine vaginal ring is the first method to fulfil the promise of a fully reversible, long-acting, woman-initiated approach for discreet HIV-1 prevention.

Clinical and Virologic Outcomes Following Initiation of Antiretroviral Therapy Among Seroconverters in the Microbicide Trials Network-020 Phase III Trial of the Dapivirine Vaginal Ring

BACKGROUND

A vaginal ring containing dapivirine, a non-nucleoside human immunodeficiency virus (HIV)-1 reverse transcriptase inhibitor (NNRTI), was safe and effective in preventing HIV-1 infection in African women. We examined the impact of dapivirine ring use at the time of HIV-1 acquisition on subsequent HIV-1 disease progression and responses to NNRTI-containing antiretroviral therapy (ART).

METHODS

HIV-1 disease progression and virologic failure following initiation of ART were assessed among women who acquired HIV-1 while participating in Microbicide Trials Network-020, a randomized, placebo-controlled trial of a monthly, dapivirine vaginal ring.

RESULTS

Among the 158 participants who acquired HIV-1 (65 dapivirine, 93 placebo), no differences between dapivirine and placebo participants were observed in CD4+ cell counts or plasma HIV-1 RNA over the first year after infection (prior to ART). During follow-up, 100/158 (63%) participants initiated NNRTI-containing ART (dapivirine: 39/65; placebo: 61/93); the median time to HIV-1 RNA <200 copies/ml was approximately 90 days for both dapivirine and placebo ring recipients (log-rank P = .40). Among the 81 participants with at least 6 months of post-ART follow-up, 19 (24%) experienced virologic failure (dapivirine: 6/32, 19%; placebo: 13/39, 27%; P = .42).

CONCLUSIONS

The acquisition of HIV-1 infection during dapivirine or placebo treatment in ASPIRE did not lead to differences in HIV-1 disease progression. After the initiation of NNRTI-containing ART, dapivirine and placebo participants had similar times to virologic suppression and risks of virologic failure. These results provide reassurance that NNRTI-based ART regimens are effective among women who acquired HIV-1 while receiving the dapivirine vaginal ring.

CLINICAL TRIALS REGISTRATION

NCT016170096 and NCT00514098.

The Power of the Shared Experience: MTN-020/ASPIRE Trial Participants' Descriptions of Peer Influence on Acceptability of and Adherence to the Dapivirine Vaginal Ring for HIV Prevention

Women are disproportionately at risk of acquiring HIV in East and Southern Africa, despite global declines in incidence. Female-initiated HIV prevention methods, like the dapivirine vaginal ring, are needed to end the HIV epidemic. In-depth interviews and focus groups retrospectively explored peer influence on acceptability of and adherence to the ring during the ASPIRE trial, a phase III placebo-controlled trial. Results were analyzed using an inductive analytic approach. Study participants (peers) of all ages and adherence groups developed important interpersonal connections and reported being more open and honest with each other than with external peers or study staff. Study peers who knew each other prior to joining appeared to have a stronger influence on each other's adherence than peers who met in the study. External peers provided primarily negative input about the ring and study, which sometimes led to ring removals. Peers' influence on each other's behavior in both prosocial and detrimental manners could have repercussions on adherence to a biomedical intervention, and consequently, individual disease risk and clinical trial outcomes. Future ring demonstration and implementation studies could use peer networks to intentionally influence uptake and adherence to the ring.

Impact of Partner-Related Social Harms on Women's Adherence to the Dapivirine Vaginal Ring During a Phase III Trial

Background:

Long-acting female-initiated methods such as the dapivirine ring may give women greater agency in HIV-1 prevention. However, social harms, defined as nonmedical adverse consequences of study participation or dapivirine ring use, may reduce product adherence and consequently HIV-1 protection.

Methods:

We assessed whether experiencing social harms from male partners was associated with lower adherence to the dapivirine ring in the MTN-020/ASPIRE trial. Reports of social harms were solicited quarterly. Low adherence was defined by plasma dapivirine levels ≤95 pg/mL or residual dapivirine levels in returned rings >23.5 mg.

Results:

Among 2629 women enrolled in ASPIRE, 85 (3.2%) reported 87 social harms during a median follow-up of 1.6 years. Women were significantly more likely to have low adherence, measured by plasma dapivirine levels, at visits with a social harm in the past month than at visits where no social harm was reported (adjusted risk ratio 2.53, 95% confidence interval: 1.37 to 4.66, P = 0.003). There was no association for social harms reported ≥1 month prior, suggesting an acute, short-term effect. Women were significantly more likely to not return a ring at visits with a social harm reported (adjusted risk ratio 24.70, 95% confidence interval: 18.57 to 32.85, P < 0.001). In rings that were returned, social harms were not associated with residual dapivirine levels.

Conclusions:

Although social harms were uncommon (<5% of women with >1 year of use), participants reporting social harms by male partners had lower adherence to the dapivirine ring. Strategies to mitigate nonadherence to product use related to social harms should be evaluated in future studies of female-controlled HIV-1 prevention options.

Reaching at-risk women for PrEP delivery: What can we learn from clinical trials in sub-Saharan Africa?

INTRODUCTION

ARV-based pre-exposure prophylaxis (PrEP) has the potential to avert many new HIV infections, yet little is known about how to reach women at high risk for HIV infection and motivate them to initiate PrEP. Clinical trials have succeeded in recruiting at-risk participants, evidenced by control arm HIV incidence ≥3% (defined by the World Health Organization as "substantial risk"). We examined experiences from HIV prevention trials to document recruitment strategies and identify practical, potentially effective strategies for reaching women in real-world PrEP delivery.

METHODS

We conducted semi-structured qualitative phone interviews with 31 staff from five countries who had worked on one or more of seven ARV-based HIV prevention clinical trials. Questions explored recruitment strategies used to reach women at risk of HIV and to successfully communicate about PrEP (inclusive of oral and vaginal formulations). We structurally coded data in NVivo and analyzed codes to derive themes. We conducted results interpretation webinars with research and programmatic stakeholders to validate findings and develop recommendations.

RESULTS

Clinical trial researchers employed a range of recruitment strategies to recruit at-risk women. They recommended engaging the local community and potential PrEP users via community events, meetings with gatekeepers, and use of community advisory boards; and they encouraged interpersonal communication like presentations in waiting rooms and door-to-door recruitment to address personal concerns and prevent misinformation. Participants also stressed the importance of addressing the challenges that already exist within the health system to create a more enabling environment and delivering positive messages through a variety of communication channels to normalize PrEP.

CONCLUSIONS

Findings from this study provide important insights into potentially effective ways for countries currently rolling out oral PrEP to reach at-risk women with information about PrEP and promote uptake.

Reported oral and anal sex among adolescents and adults reporting heterosexual sex in sub-Saharan Africa: a systematic review

BACKGROUND

Oral and anal sexual behaviours are increasingly reported among adolescents and adults reporting heterosexual sex in peer-reviewed journals in high income countries, but less is known about these behaviours in low and middle-income countries, especially in sub-Saharan Africa. The aim of this systematic review is to describe the prevalence of, and motivations for, oral and anal sex among adolescents and adults reporting heterosexual sex in sub-Saharan Africa.

METHODS

A systematic review of published articles that reported oral and or anal sex in sub-Saharan Africa was conducted from seven databases up to and including 30th August 2018.

RESULTS

Of 13,592 articles, 103 met the inclusion criteria. The prevalence of reporting ever practising oral sex among adolescents, university students and a combined population of adolescents/adults ranged from 1.7-26.6%, 5.0-46.4% and 3.0-47.2% respectively. Similarly, prevalences of reported ever practising anal sex ranged from 6.4-12.4% among adolescents, 0.3-46.5% among university students and 4.3-37.8% amongst combined population of adolescents and adults. Higher prevalences of oral and anal sex were reported among populations at high-risk for sexually transmitted infections and HIV and university students and, in most studies, both behaviours were more commonly reported by males than females. Heterosexual oral and anal sexual acts were associated with some high-risk behaviours such as inconsistent condom use and multiple sexual partners.

CONCLUSION

Reported oral and anal sex between men and women are prevalent behaviours in sub-Saharan Africa. Health professionals and policy makers should be aware of these behaviours and their potential associated health risks.

"The state of mind tells me it's dirty": menstrual shame amongst women using a vaginal ring in Sub Saharan Africa

Socio-cultural beliefs and practices surrounding menses influence women's sexual and reproductive health behaviors and decision-making. We analyzed menstrual experiences within the context of the MTN-020/ASPIRE clinical trial during which women were asked to use a monthly vaginal ring for HIV prevention. The qualitative component of the trial was conducted during February 2013-June 2015, included interviews and focus group discussions with 214 women aged 18-42, in Malawi, Zimbabwe, Uganda, and South Africa. Emotions of shame, embarrassment and disgust relating to menses emerged. Menstruation was referred to using euphemistic terms or language about dirtiness. Women were uncomfortable touching their own menstrual blood when removing vaginal rings and felt embarrassed about study staff seeing blood on returned rings. Despite reassurances, women felt ashamed performing study procedures while menstruating, leading to missed study visits. Women's aversion to menstrual blood was linked to narratives about avoiding sex during menses and beliefs about its potential harms. Women associated men's disgust pertaining to menstrual blood with men's willingness to use condoms for sex only during menses, highlighting another way through which socio-cultural beliefs and practices around menstruation affect HIV protective behaviours. These findings provide novel insight into menstrual shame among women in these four countries.

Adult gonorrhea, chlamydia and syphilis prevalence, incidence, treatment and syndromic case reporting in South Africa: Estimates using the Spectrum-STI model, 1990-2017

OBJECTIVES

To estimate trends in prevalence and incidence of syphilis, gonorrhea and chlamydia in adult men and women in South Africa.

METHODS

The Spectrum-STI tool estimated trends in prevalence and incidence of active syphilis, gonorrhea and chlamydia, fitting South African prevalence data. Results were used, alongside programmatic surveillance data, to estimate trends in incident gonorrhea cases resistant to first-line treatment, and the reporting gap of symptomatic male gonorrhea and chlamydia cases treated but not reported as cases of urethritis syndrome.

RESULTS

In 2017 adult (15-49 years) the estimated female and male prevalences for syphilis were 0.50% (95% CI: 0.32-0.80%) and 0.97% (0.19-2.28%), for gonorrhea 6.6% (3.8-10.8%) and 3.5% (1.7-6.1%), and for chlamydia 14.7% (9.9-21%) and 6.0% (3.8-10.4%), respectively. Between 1990 and 2017 the estimated prevalence of syphilis declined steadily in women and men, probably in part reflecting improved treatment coverage. For gonorrhea and chlamydia, estimated prevalence and incidence showed no consistent time trend in either women or men. Despite growing annual numbers of gonorrhea cases - reflecting population growth - the estimated number of first line treatment-resistant gonorrhea cases did not increase between 2008 and 2017, owing to changes in first-line antimicrobial treatment regimens for gonorrhea in 2008 and 2014/5. Case reporting completeness among treated male urethritis syndrome episodes was estimated at 10-28% in 2017.

CONCLUSION

South Africa continues to suffer a high STI burden. Improvements in access and quality of maternal, STI and HIV health care services likely contributed to the decline in syphilis prevalence. The lack of any decline in gonorrhea and chlamydia prevalence highlights the need to enhance STI services beyond clinic-based syndromic case management, to reinvigorate primary STI and HIV prevention and, especially for women, to screen for asymptomatic infections.

The relationship between vaginal ring use and intimate partner violence and social harms: formative research outcomes from the CHARISMA study in Johannesburg, South Africa

Despite being designed for autonomous use, research suggests partner approval is often in women's microbicide use. Microbicide study participants have described many ways product use affects relationships, from improving sexual pleasure to increasing harm, including exacerbating intimate partner violence (IPV). As the dapivirine ring proceeds closer to licensure, supporting women's agency to use microbicides safely is a priority. We conducted 42 in-depth interviews with former participants of the Microbicide Trials Network (MTN)-020 trial of the dapivirine vaginal ring and their male partners in Johannesburg, South Africa, to explore how ring use and partnership dynamics interacted. We sampled women who reported harms or partner non-support and women with supportive partners. Male and female narratives revealed high background levels of IPV. Women described how study participation/ring use exacerbated violence, and for a few couples served as a rationale for additional abuse. In response, women described feeling powerless and fearful of conflict, resulting in product nonuse. For one participant violence was reduced, and for several others, empowerment was sparked. These findings suggest future providers have the opportunity to shift more women from a place of fear/violence to one of safety/empowerment through the integration of IPV screening and relationship counselling.

Reasons for nonadherence to the dapivirine vaginal ring: narrative explanations of objective drug-level results

OBJECTIVE(S)

MTN-020/ASPIRE trial and IPM-027/Ring Study recently proved the dapivirine vaginal ring was safe and effective with consistent use. To optimize the ring's impact, the barriers and facilitators to ring adherence must be understood and addressed.

METHODS

Former ASPIRE participants were stratified by age group (18-21; 22-45) and randomly selected at seven sites in Malawi, South Africa, Uganda and Zimbabwe, 12-17 months after trial exit. Using in-depth interviews or focus group discussions, ring use barriers were explored using structured guides and visual tools including individual-level depictions of dapivirine levels detected in plasma and returned rings.

RESULTS

A total of 187 were enrolled; 37% were 18-21 years when they began ASPIRE. Most (75%) had drug-level results, suggesting inconsistent ring use throughout ASPIRE. Participants viewed themselves as adherent, while simultaneously describing regular instances and reasons for ring removal (e.g. for sex or menses). Less adherent women reported fears that partners would oppose the ring or feel it during sex. High adherers expressed altruistic motivations for ring use. Women of all ages attributed young women's nonadherence to their tendency to be less 'serious' about the future, HIV prevention and the study; motivated predominantly by benefits; more fearful of fertility-related consequences; and to having less relationship control.

CONCLUSION

When presented with objective adherence data, participants provided reasons for intermittent ring use, while simultaneously portraying themselves as consistent ring users. Further research is needed to understand how women could use the ring in a way that fits into the context of their relationships and their lives while still conferring adequate HIV prophylaxis.

Implementation of a Novel Adherence Monitoring Strategy in a Phase III, Blinded, Placebo-Controlled, HIV-1 Prevention Clinical Trial

BACKGROUND

Placebo-controlled HIV-1 prevention trials of pre-exposure prophylaxis (PrEP) have not generally used concurrent measurement of adherence because of the potential risk of unblinding. However, several pre-exposure prophylaxis trials for HIV-1 prevention among women failed to show effectiveness because of low product adherence. Evaluation of product adherence objectively during a study provides the opportunity for strengthening adherence activities at sites having low adherence.

METHODS

During MTN-020/ASPIRE, a phase III, placebo-controlled trial of the dapivirine intravaginal ring, we implemented an adherence monitoring system. Monitoring began in quarter 1 (Q1) 2013 and continued through the conclusion of the trial. Blood plasma was collected quarterly and tested for dapivirine concentrations while maintaining blinding among study team members involved in participant management. Dapivirine concentrations >95 pg/mL, reflecting >8 hours of continuous use, were assessed as signaling product use. Study leadership monitored results on a monthly basis and provided feedback to site investigators. Experiences were shared across sites to motivate staff and counsel participants to strive toward higher adherence levels.

RESULTS

An upward trend in adherence was observed (P < 0.0001); the proportion of samples from subjects in the active arm with dapivirine >95 pg/mL increased from 63% in Q1 2013 to 84% by Q1 2015.

CONCLUSIONS

Ongoing drug level testing as a marker of adherence in MTN-020/ASPIRE demonstrates the feasibility of real-time adherence monitoring while maintaining study blinding at the level of participants, sites, and study leadership. This approach is novel for large-scale effectiveness studies for HIV-1 prevention.

Historical development of vaginal microbicides to prevent sexual transmission of HIV in women: from past failures to future hopes

Infection with human immunodeficiency virus (HIV) remains a global public health concern and is particularly serious in low- and middle-income countries. Widespread sexual violence and poverty, among other factors, increase the risk of infection in women, while currently available prevention methods are outside the control of most. This has driven the study of vaginal microbicides to prevent sexual transmission of HIV from men to women in recent decades. The first microbicides evaluated were formulated as gels for daily use and contained different substances such as surfactants, acidifiers and monoclonal antibodies, which failed to demonstrate efficacy in clinical trials. A gel containing the reverse transcriptase inhibitor tenofovir showed protective efficacy in women. However, the lack of adherence by patients led to the search for dosage forms capable of releasing the active principle for longer periods, and hence to the emergence of the vaginal ring loaded with dapivirine, which requires a monthly application and is able to reduce the sexual transmission of HIV. The future of vaginal microbicides will feature the use of alternative dosage forms, nanosystems for drug release and probiotics, which have emerged as potential microbicides but are still in the early stages of development. Protecting women with vaginal microbicide formulations would, therefore, be a valuable tool for avoiding sexual transmission of HIV.

Acceptability and use of a dapivirine vaginal ring in a phase III trial

BACKGROUND

The MTN-020/ASPIRE trial evaluated the safety and effectiveness of the dapivirine vaginal ring for prevention of HIV-1 infection among African women. A nested qualitative component was conducted at six of 15 study sites in Uganda, Malawi, Zimbabwe and South Africa to evaluate acceptability of and adherence to the ring.

METHOD

Qualitative study participants (n = 214) were interviewed with one of three modalities: single in-depth interview, up to three serial interviews or an exit Focus Group Discussion. Using semistructured guides administered in local languages, 280 interviews were audio-recorded, transcribed, translated, coded and analyzed.

RESULTS

We identified three key findings: first, despite initial fears about the ring's appearance and potential side effects, participants grew to like it and developed a sense of ownership of the ring once they had used it. Second, uptake and sustained adherence challenges were generally overcome with staff and peer support. Participants developed gradual familiarity with ring use through trial progression, and most reported that it was easy to use and integrate into their lives. Using the ring in ASPIRE was akin to joining a team and contributing to a broader, communal good. Third, the actual or perceived dynamics of participants' male partner relationship(s) were the most consistently described influence (which ranged from positive to negative) on participants' acceptability and use of the ring.

CONCLUSION

It is critical that demonstration projects address challenges during the early adoption stages of ring diffusion to help achieve its potential public health impact as an effective, long-acting, female-initiated HIV prevention option addressing women's disproportionate HIV burden.

Preferences for Long-Acting Pre-exposure Prophylaxis (PrEP), Daily Oral PrEP, or Condoms for HIV Prevention Among U.S. Men Who Have Sex with Men

HIV prevention method preferences were evaluated among 512 U.S. men who have sex with men (MSM; median age: 22 years). Approximately 90 % consistently preferred one option across pairwise comparisons of condoms, daily oral pre-exposure prophylaxis (PrEP), and long-acting PrEP delivered via either an injectable or one of two types of PrEP implants differing in visibility. Condoms were most frequently preferred (33.8 %), followed by non-visible implants (21.5 %), and oral PrEP (17.0 %); HIV risk was reported by more choosing implants. In a follow-up question comparing the four PrEP options only, daily oral pills and non-visible implants were most frequently preferred (35.5 and 34.3 %, respectively), followed by injections (25.2 %) and visible implants (4.3 %). An inductive, open-coding approach determined that convenience, duration of protection, and privacy were the most commonly cited reasons for a PrEP method choice, and associated with self-report of HIV risk. Tailoring PrEP product development to privacy and other concerns important to those at highest HIV risk may improve HIV prevention.

Frequent Cross-Resistance to Dapivirine in HIV-1 Subtype C-Infected Individuals after First-Line Antiretroviral Therapy Failure in South Africa

A vaginal ring containing dapivirine (DPV) has shown moderate protective efficacy against HIV-1 acquisition, but the activity of DPV against efavirenz (EFV)- and nevirapine (NVP)-resistant viruses that could be transmitted is not well defined. We investigated DPV cross-resistance of subtype C HIV-1 from individuals on failing NVP- or EFV-containing antiretroviral therapy (ART) in South Africa. Plasma samples were obtained from individuals with >10,000 copies of HIV RNA/ml and with HIV-1 containing at least one non-nucleoside reverse transcriptase (NNRTI) mutation. Susceptibility to NVP, EFV, and DPV in TZM-bl cells was determined for recombinant HIV-1_LAI containing bulk-amplified, plasma-derived, full-length reverse transcriptase sequences. Fold change (FC) values were calculated compared with a composite 50% inhibitory concentration (IC₅₀) from 12 recombinant subtype C HIV-1_LAI plasma-derived viruses from treatment-naive individuals in South Africa. A total of 25/100 (25%) samples showed >500-FCs to DPV compared to treatment-naive samples with IC₅₀s exceeding the maximum DPV concentration tested (132 ng/ml). A total of 66/100 (66%) samples displayed 3- to 306-FCs, with a median IC₅₀ of 17.6 ng/ml. Only 9/100 (9%) samples were susceptible to DPV (FC < 3). Mutations L100I and K103N were significantly more frequent in samples with >500-fold resistance to DPV compared to samples with a ≤500-fold resistance. A total of 91% of samples with NNRTI-resistant HIV-1 from individuals on failing first-line ART in South Africa exhibited ≥3-fold cross-resistance to DPV. This level of resistance exceeds expected plasma concentrations, but very high genital tract DPV concentrations from DPV ring use could block viral replication. It is critically important to assess the frequency of transmitted and selected DPV resistance in individuals using the DPV ring.

How common and frequent is heterosexual anal intercourse among South Africans? A systematic review and meta-analysis

BACKGROUND

HIV is transmitted more effectively during anal intercourse (AI) than vaginal intercourse (VI). However, patterns of heterosexual AI practice and its contribution to South Africa's generalized epidemic remain unclear. We aimed to determine how common and frequent heterosexual AI is in South Africa.

METHODS

We searched for studies reporting the proportion practising heterosexual AI (prevalence) and/or the number of AI and unprotected AI (UAI) acts (frequency) in South Africa from 1990 to 2015. Stratified random-effects meta-analysis by sub-groups was used to produce pooled estimates and assess the influence of participant and study characteristics on AI prevalence. We also estimated the fraction of all sex acts which were AI or UAI and compared condom use during VI and AI.

RESULTS

Of 41 included studies, 31 reported on AI prevalence and 14 on frequency, over various recall periods. AI prevalence was high across different recall periods for sexually active general-risk populations (e.g. lifetime = 18.4% [95%CI:9.4-27.5%], three-month = 20.3% [6.1-34.7%]), but tended to be even higher in higher-risk populations such as STI patients and female sex workers (e.g. lifetime = 23.2% [0.0-47.4%], recall period not stated = 40.1% [36.2-44.0%]). Prevalence was higher in studies using more confidential interview methods. Among general and higher-risk populations, 1.2-40.0% and 0.7-21.0% of all unprotected sex acts were UAI, respectively. AI acts were as likely to be condom protected as vaginal acts.

CONCLUSION

Reported heterosexual AI is common but variable among South Africans. Nationally and regionally representative sexual behaviour studies that use standardized recall periods and confidential interview methods, to aid comparison across studies and minimize reporting bias, are needed. Such data could be used to estimate the extent to which AI contributes to South Africa's HIV epidemic.

Use of a Vaginal Ring Containing Dapivirine for HIV-1 Prevention in Women

BACKGROUND

Antiretroviral medications that are used as prophylaxis can prevent acquisition of human immunodeficiency virus type 1 (HIV-1) infection. However, in clinical trials among African women, the incidence of HIV-1 infection was not reduced, probably because of low adherence. Longer-acting methods of drug delivery, such as vaginal rings, may simplify use of antiretroviral medications and provide HIV-1 protection.

METHODS

We conducted a phase 3, randomized, double-blind, placebo-controlled trial of a monthly vaginal ring containing dapivirine, a non-nucleoside HIV-1 reverse-transcriptase inhibitor, involving women between the ages of 18 and 45 years in Malawi, South Africa, Uganda, and Zimbabwe.

RESULTS

Among the 2629 women who were enrolled, 168 HIV-1 infections occurred: 71 in the dapivirine group and 97 in the placebo group (incidence, 3.3 and 4.5 per 100 person-years, respectively). The incidence of HIV-1 infection in the dapivirine group was lower by 27% (95% confidence interval [CI], 1 to 46; P=0.046) than that in the placebo group. In an analysis that excluded data from two sites that had reduced rates of retention and adherence, the incidence of HIV-1 infection in the dapivirine group was lower by 37% (95% CI, 12 to 56; P=0.007) than that in the placebo group. In a post hoc analysis, higher rates of HIV-1 protection were observed among women over the age of 21 years (56%; 95% CI, 31 to 71; P<0.001) but not among those 21 years of age or younger (-27%; 95% CI, -133 to 31; P=0.45), a difference that was correlated with reduced adherence. The rates of adverse medical events and antiretroviral resistance among women who acquired HIV-1 infection were similar in the two groups.

CONCLUSIONS

A monthly vaginal ring containing dapivirine reduced the risk of HIV-1 infection among African women, with increased efficacy in subgroups with evidence of increased adherence. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01617096 .).

Long-term follow-up of HIV seroconverters in microbicide trials - rationale, study design, and challenges in MTN-015

BACKGROUND

As the effect of biomedical prevention interventions on the natural history of HIV-1 infection in participants who seroconvert is unknown, the Microbicide Trials Network (MTN) established a longitudinal study (MTN-015) to monitor virologic, immunological, and clinical outcomes, as well as behavioral changes among women who become HIV-infected during MTN trials. We describe the rationale, study design, implementation, and enrollment of the initial group of participants in the MTN seroconverter cohort.

METHODS

Initiated in 2008, MTN-015 is an ongoing observational cohort study enrolling participants who acquire HIV-1 infection during effectiveness studies of candidate microbicides. Eligible participants from recently completed and ongoing MTN trials are enrolled after seroconversion and return for regular follow-up visits with clinical and behavioral data collection. Biologic samples including blood and genital fluids are stored for future testing.

RESULTS

MTN-015 was implemented initially at six African sites and enrolled 100/139 (72%) of eligible women who seroconverted in HIV Prevention Trials Network protocol 035 (HPTN 035, conducted by the MTN). The median time from seroconversion in HPTN 035 to enrollment in MTN-015 was 18 months. Retention was good with >70% of visits completed. Implementation challenges included regulatory reviews, translation, and testing of questionnaires, and site readiness.

CONCLUSIONS

Enrollment of HIV-seroconverters into a longitudinal observational follow-up study is feasible and acceptable to participants. Data and samples collected in this protocol will be used to assess safety of investigational HIV microbicides and answer other important public health questions for HIV infected women.

A Shot in the Arm for HIV Prevention? Recent Successes and Critical Thresholds

Efforts to decrease the spread of HIV worldwide continue at a rapid pace. With the development of new biomedical interventions and findings from pivotal clinical trials, a new framework for short-term and long-term prevention strategies is emerging. It is clear that biomedical-based approaches targeted at the highest risk populations have the greatest potential to have a short-term impact. Unfortunately, challenges with adherence in healthy populations at risk are now well-recognized, and competing health care priorities in the context of fragile delivery infrastructures pose formidable obstacles to implementation. We need better ways to identify high-risk populations, sophisticated understanding of the behavioral parameters that can ensure adherence, and the development of better strategies to provide sustained delivery of preexposure prophylaxis (PrEP). In the long term, we need an effective vaccine--a path that has proven to be rocky. Research facilitating an increased understanding of immune responses and what represents effective responses to prevent HIV acquisition should facilitate progress. While we wait for that time, PrEP offers the best strategy for short-term impact.