Acceptability of the dapivirine vaginal ring for HIV-1 prevention among women reporting engagement in transactional sex.

We assessed if acceptability of the dapivirine vaginal ring for HIV prevention differed among the subgroup of women who reported engaging in transactional sex prior to enrollment in MTN-020/ASPIRE (phase III trial in Malawi, South Africa, Uganda, and Zimbabwe, 2012-2015; n = 2629). Transactional sex was defined as receipt of money, goods, gifts, drugs, or shelter in exchange for sex in the past year. Dimensions of acceptability included: ease of use and physical sensation in situ, impacts on sex, partner's opinion, and likelihood of future use. We used Poisson regression models with robust standard errors to compare risk of acceptability challenges by baseline history of transactional sex. At product discontinuation, women exchanging sex found the ring comfortable (90%), easy to insert (92%) and nearly all (96%) were likely to use the ring in the future. Women who had exchanged sex were more likely to report feeling the ring during sex (ARR 1.43, 95% CI: 1.09, 1.89; p = 0.01) and slightly more likely to mind wearing the ring during menses (ARR 1.22, 95% CI: 1.01, 1,46; p = 0.04) and during sex (ARR 1.22, 95% CI: 1.02, 1.45; p = 0.03). Messaging and counseling should include enhanced support for use during sex and menses to support optimal use.

Brief Report: Dapivirine Ring HIV-1 Prevention Effectiveness for Women Engaged in Vaginal and Anal Intercourse: Insights From Mathematical Modeling.

BACKGROUND: The dapivirine vaginal ring reduces the risk of HIV-1 acquisition in acts of vaginal intercourse (VI), and although it does not offer HIV-1 protection in acts of anal intercourse (AI), it may provide some overall risk reduction for women for whom most sex acts are vaginal. We estimated the protective effect of the ring among women with high ring adherence engaged in both VI and AI. METHODS: We developed a microsimulation model using data from the MTN-020/ASPIRE trial. Among women who reported any AI, we estimated the proportion of all sex acts that were AI. Model scenarios varied this proportion among women engaged in both VI and AI from 5% to 30%, including the trial-observed median proportion of 6.3% of all acts being AI. In primary analyses, dapivirine ring efficacy was model-calibrated at 70% for vaginal exposures and assumed to be 0% for anal exposures. RESULTS: Among highly adherent women for whom 6.3% of sex acts were AI, the ring reduced HIV-1 risk by 53% (interquartile range: 44, 60), with a decline to 26% (interquartile range: 16, 36) among women for whom 30% of acts were AI. Ring effectiveness was less than 40% among women for whom AI accounted for greater than 16% of all sex acts, although this represented less than 5% of all women in the ASPIRE trial. CONCLUSIONS: For most women, including those who engage in AI, because most HIV-1 risk occurs in acts of vaginal sex, the dapivirine vaginal ring can provide important HIV-1 protection.

Patterns of Adherence to a Dapivirine Vaginal Ring for HIV-1 Prevention Among South African Women in a Phase III Randomized Controlled Trial.

BACKGROUND: Persistent use of HIV prevention methods can be a challenge, particularly for some younger women. The long-acting, discreet, woman-centric dapivirine vaginal ring offers promise as a prevention method with less user burden, which could support continued use. We assessed dapivirine vaginal ring use to understand adherence patterns and identify characteristics influencing patterns. SETTING: Participants enrolled in South Africa in the MTN-020/ASPIRE randomized placebo-controlled trial. METHODS: We used group-based trajectory modeling to identify clusters of participants with similar longitudinal patterns of adherence in the last year of participation and potential predictors of group membership. Women with at least 1 year of follow-up were included (n = 626). RESULTS: Five adherence patterns were identified: (1) consistently high, 34%, (2) consistently moderate, 34%, (3) consistently low, 16%, (4) decreasing, 9%, and (5) increasing, 7%. Women younger than 22 years [adjusted odds ratio (AOR) 1.8, 95% confidence interval (CI): 1.0 to 3.0], using an intrauterine device (AOR 3.3, 95% CI: 1.4 to 7.8) or oral contraceptives (AOR 3.9, 95% CI: 1.7 to 8.9), experiencing menses (AOR 1.8, 95% CI: 1.1 to 3.0), and who reported inconsistent condom use (AOR 1.8, 95% CI: 1.0 to 3.3) were more likely to be classified as consistently low compared to consistently high (referent). CONCLUSIONS: Most South African women successfully persisted with a moderate or high level of use. Encouraging ring replacement with completion of menses may help to decrease concerns about hygiene and improve persistence. Associations between contraception and persistent low adherence suggest efforts may be needed to ensure contraceptive method choice does not interfere with ring use.

Prevalent human papillomavirus infection increases the risk of HIV acquisition in African women: advancing the argument for human papillomavirus immunization.

OBJECTIVE: Vaccine-preventable human papillomavirus (HPV) infection is common, especially in sub-Saharan Africa where HIV risk is also high. However, unlike other sexually transmitted infections (STIs), HPV's role in HIV acquisition is unclear. We evaluated this relationship using data from MTN-003, a clinical trial of HIV chemoprophylaxis among cisgender women in sub-Saharan Africa. DESIGN: A case-control study. METHODS: We matched 138 women who acquired HIV (cases) to 412 HIV-negative controls. Cervicovaginal swabs collected within 6 months before HIV seroconversion were tested for HPV DNA. We estimated the associations between carcinogenic (high-risk) and low-risk HPV types and types targeted by HPV vaccines and HIV acquisition, using conditional logistic regression models adjusted for time-varying sexual behaviors and other STIs. RESULTS: Mean age was 23 (±4) years. Any, high-risk and low-risk HPV was detected in 84, 74 and 66% of cases, and 65, 55 and 48% of controls. Infection with at least two HPV types was common in cases (67%) and controls (49%), as was infection with nonavalent vaccine-targeted types (60 and 42%). HIV acquisition increased with any [adjusted odds ratio (aOR) 2.5, 95% confidence interval (95% CI) 1.3-4.7], high-risk (aOR 2.6, 95% CI 1.5-4.6) and low-risk (aOR 1.8, 95% CI 1.1-2.9) HPV. Each additional type detected increased HIV risk by 20% (aOR 1.2, 95% CI 1.1-1.4). HIV acquisition was associated with HPV types targeted by the nonavalent (aOR 2.1, 95% CI 1.3-3.6) and quadrivalent vaccines (aOR 1.9, 95% CI 1.1-3.2). CONCLUSION: HPV infection is associated with HIV acquisition in sub-Saharan African women. In addition to preventing HPV-associated cancers, increasing HPV vaccination coverage could potentially reduce HIV incidence.

Impact and experience of participant engagement activities in supporting dapivirine ring use among participants enrolled in the phase III MTN-020/ASPIRE study.

BACKGROUND: Low adherence to investigational products can negatively impact study outcomes, limiting the ability to demonstrate efficacy. To continue advancing potential new HIV prevention technologies, efforts are needed to improve adherence among study participants. In MTN-020/ASPIRE, a phase III randomized, double-blind, placebo-controlled study of the dapivirine vaginal ring carried out across 15 sites in sub-Saharan Africa, a multifaceted approach to adherence support was implemented, including a strong focus on participant engagement activities (PEAs). In this manuscript, we describe PEAs and participant attendance, and analyze the potential impact of PEAs on ring use. METHODS: All sites implemented PEAs and submitted activity and attendance reports to the study management team throughout the study. Participant demographics were collected via case report forms. Residual dapivirine remaining in the last ring returned by each participant was used to estimate drug released from the ring, which was then adjusted for time participants had the ring to calculate probable use categorized into three levels (low/intermittent/high). Product use was connected to PEA attendance using participant identification numbers. We used multivariate Poisson regression with robust standard errors to explore differences in ring use between PEA attendance groups and reviewed qualitative reports for illustrative quotes highlighting participant experiences with PEAs. RESULTS: 2312 of 2629 study participants attended at least one of 389 PEAs conducted across sites. Participant country and partner knowledge of study participation were most strongly associated with PEA attendance (p < 0.005) with age, education, and income status also associated with event attendance (p < 0.05). When controlling for these variables, participants who attended at least one event were more likely to return a last ring showing at least some use (RR = 1.40) than those who never attended an event. There was a stronger correlation between a last returned ring showing use and participant attendance at multiple events (RR = 1.52). CONCLUSIONS: Our analysis supports the growing body of work illustrating the importance of meaningfully engaging research participants to achieve study success and aligns with other analyses of adherence support efforts during ASPIRE. While causation between PEA attendance and product use cannot be established, residual drug levels in returned rings strongly correlated with participant attendance at PEAs, and the benefits of incorporating PEAs should be considered when designing future studies of investigational products.

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.

The Influence of Perceived Dapivirine Vaginal Ring Effectiveness on Social Disclosure and Ring Adherence.

We analyzed data from 1428 users of the dapivirine vaginal ring, who participated in the MTN-020/ASPIRE phase III trial and subsequent open-label extension MTN-025/HOPE trial, to examine relationships between perceived ring protection, social disclosures, and self-reported ring adherence. In HOPE, 77% perceived the ring to be highly effective, and this view was associated with speaking: (a) to a greater number of people about the study, (b) with other participants, (c) to more people who were in favor of the ring, and (d) to more people whose opinions were valued. Reported adherence was not directly associated with perceived protection but was associated with disclosing to someone who was in favor of the ring. These findings suggest the importance of women's internalized ideas about the protective benefits of the DVR in sharing information about the ring and the importance of social support on adherence.

Acceptability of the Dapivirine Vaginal Ring for HIV-1 Prevention and Association with Adherence in a Phase III Trial.

We evaluated the acceptability of the 25 mg dapivirine vaginal ring (DVR) as an HIV prevention intervention and its influence on DVR adherence in the MTN-020/ASPIRE phase III trial. Acceptability measures were captured using ACASI at month 3 and end of product use (median 24 months, IQR 15-30). Monthly returned rings were classified as nonadherent if dapivirine release rate was ≤ 0.9 mg/month. Associations between acceptability measures and nonadherence were estimated using Poisson regression models with robust standard errors. At month 3 (N = 2334), 88% reported DVR was comfortable, 80% were unaware of it during daily activities, and 74% never felt it during sex. At exit, 66% were 'very likely' to use DVR in the future. Acceptability was found to differ significantly by country across several measures including wearing the ring during sex, during menses, partner acceptability, impact on sexual pleasure and willingness to use the ring in the future. Risk of nonadherence at month 12 was elevated if DVR was felt during sex at month 3 (aRR 1.67, 95% CI 1.26, 2.23). Risk of nonadherence in the last year of study participation was elevated if, at exit, participants minded wearing during sex (aRR 2.08, 95% CI 1.52, 2.85), during menses (aRR 1.57, 95% CI 1.06, 2.32), reported a problematic change to the vaginal environment (aRR 1.57, 95% CI 1.12, 2.21), and were not "very likely" to use DVR in the future (aRR 1.31, 95% CI 1.02, 1.68). DVR acceptability was overall high yet varied by country. Addressing perceived ring interference with sex, menses, or problematic changes to the vaginal environment in future interventions could help improve adherence, as could embracing sex-positive messaging related to ring use and increased pleasure.Trial Registration ClinicalTrials.gov Identifier: NCT01617096.

Elevated Risk of Bacterial Vaginosis Among Users of the Copper Intrauterine Device: A Prospective Longitudinal Cohort Study.

BACKGROUND: Limited evidence suggests that the nonhormonal contraceptive copper intrauterine device (Cu-IUD) may increase bacterial vaginosis (BV) risk, possibly due to increased volume and duration of menses, a common side effect of Cu-IUD use. Although increases in bleeding typically resolve within 6-12 months following initiation, evaluations of the association between Cu-IUD and BV have not included more than 6 months of follow-up. METHODS: This secondary analysis of a human immunodeficiency virus type 1 prevention trial included 2585 African women ages 18-45 followed for up to 33 months. Women reported contraceptive use each month. BV was evaluated by Nugent score in 6-monthly intervals and, if clinically indicated, by Amsel criteria. Andersen-Gill proportional hazards models were used to (1) evaluate BV risk among Cu-IUD users relative to women using no/another nonhormonal contraceptive and (2) test changes in BV frequency before, while using, and following Cu-IUD discontinuation. RESULTS: BV frequency was highest among Cu-IUD users at 153.6 episodes per 100 person-years (95% confidence interval [CI]: 145.2, 162.4). In adjusted models, Cu-IUD users experienced 1.28-fold (95% CI: 1.12, 1.46) higher BV risk relative to women using no/another nonhormonal contraception. Compared to the 6 months prior to initiation, BV risk was 1.52-fold (95% CI: 1.16, 2.00) higher in the first 6 months of Cu-IUD use and remained elevated over 18 months of use (P < .05). Among women who discontinued Cu-IUD, BV frequency was similar to pre-initiation rates within 1 year. CONCLUSIONS: Cu-IUD users experienced elevated BV risk that persisted throughout use. Women and their providers may wish to consider BV risk when discussing contraceptive options.

Brief Report: Anal Intercourse, HIV-1 Risk, and Efficacy in a Trial of a Dapivirine Vaginal Ring for HIV-1 Prevention.

OBJECTIVES: To describe receptive anal intercourse (RAI) behaviors and correlates in a cohort of sub-Saharan African women, evaluate the association of RAI with HIV-1 risk, and evaluate whether the HIV-1 prevention efficacy of a dapivirine vaginal ring differs among women who reported RAI. DESIGN: Secondary analysis of the MTN-020/ASPIRE trial, a randomized, double-blind, placebo-controlled trial evaluating a dapivirine vaginal ring for HIV-1 prevention. METHODS: At enrollment and month 3, women reported RAI in the prior 3 months in audio computer-assisted self-interviews. We evaluated associations between RAI and participant characteristics with χ and t-tests adjusted for study site. Cox proportional hazards models stratified by study site tested the association of RAI with HIV-1 acquisition and effect modification by RAI. RESULTS: Eighteen percent of women reported any RAI at enrollment and/or month 3, with a median of 2 (interquartile range: 1-4) RAI acts in the prior 3 months, accounting for 1.5% of total sex acts. RAI prevalence was higher among women with lower educational attainment and those reporting transactional sex. In adjusted models, RAI was not associated with HIV-1 acquisition (aHR: 0.93, 95% CI: 0.57 to 1.54). The ring reduced HIV-1 risk by 27% (95% CI: -5 to 49) among women reporting no RAI and by 18% (95% CI: -57 to 57) among women reporting any RAI (interaction P-value = 0.77). CONCLUSIONS: RAI was modestly infrequent and was not associated with reduced HIV-1 protection from the ring, suggesting that, in populations with rates of RAI similar to this cohort, RAI may not appreciably reduce the population-level impact of the dapivirine vaginal ring.

Use of the dapivirine vaginal ring and effect on cervical cytology abnormalities.

OBJECTIVE: We aimed to determine if the dapivirine vaginal ring and the ring device alone (flexible silicone matrix polymer) was associated with the development of cervical cytology abnormalities. DESIGN: Secondary analysis comparing cervical cytology results between two randomized controlled microbicide trials (MTN-020/ASPIRE and MTN-003/VOICE). METHODS: Data from ASPIRE, a phase III, placebo-controlled trial of the dapivirine vaginal ring, were used in this analysis. Cervical cytology smears were evaluated at baseline and at the final visit with product use. We compared cytology results between women randomized to dapivirine versus placebo vaginal ring. We further assessed for the effect of the vaginal ring device on cervical cytology by comparing results with data from the oral placebo arm of VOICE, a prior HIV-1 prevention trial conducted in a similar population. RESULTS: Cervical cytology results for 2394 women from ASPIRE (1197 per study arm) were used in this analysis; median time between baseline and final visit with product use was 22.1 months. Cytology smear findings were comparable between dapivirine and placebo vaginal ring arms: at final visit, normal: 90.6 versus 91.5%, ASC-US//LSIL: 7.8 versus 7.4%, ASC-H/HSIL/AGC/AGC-favor neoplastic: 1.7 versus 1.1%, P = 0.44. Cytology data from VOICE had findings (normal: 87.8%, ASC-US/LSIL: 9.8%, ASC-H/HSIL/AGC/AGC-favor neoplastic: 2.4%) comparable with that of both dapivirine (P = 0.93) and placebo vaginal ring arms (P = 0.24). CONCLUSION: These findings indicate that neither use of the dapivirine vaginal ring nor the vaginal ring device alone, over a period of 2 years, is associated with development of cervical cytology abnormalities that could lead to precancerous or cancerous lesions.

Social harms in female-initiated HIV prevention method research: state of the evidence.

OBJECTIVES: Assessment of safety is an integral part of real-time monitoring in clinical trials. In HIV prevention research, safety of investigational products and trial participation has been expanded to include monitoring for 'social harms', generally defined as negative consequences of trial participation that may manifest in social, psychological, or physical ways. Further research on social harms within HIV prevention research is needed to understand the potential safety risks for women and advance the implementation of prevention methods in real-world contexts. METHODS: Secondary analysis of quantitative data from three randomized, double-blind, placebo-controlled trials of microbicide candidates in sub-Saharan Africa was conducted. Additionally, we assessed data from two prospective cohort studies that included participants who became HIV-positive or pregnant during parent trials. RESULTS: Social harms reporting was low across the largest and most recent microbicide studies. Social harm incidence per 100 person-years ranged from 1.10 (95% CI 0.78-1.52) to 3.25 (95% CI 2.83-3.74) in the phased trials. Reporting differed by dosing mechanism (e.g. vaginal gel, oral tablet, ring) and study, most likely as a function of measurement differences. Social harms were most frequently associated with male partners, rather than, for example, experiences of stigma in the community. CONCLUSION: Measurement and screening for social harms is an important component of conducting ethical research of novel HIV prevention methods. To date, social harm incidence reported in microbicide trials has been relatively low (<4% per 100 person-years), and the majority have been partner-related events. However, any incidence of social harm within the context of HIV prevention is important to capture and understand for the safety of individuals, and for the successful impact of prevention methods in a real-world context.

HIV disease progression among women following seroconversion during a tenofovir-based HIV prevention trial.

BACKGROUND: Little is known regarding HIV disease outcomes among individuals who become infected with HIV while receiving antiretroviral medications for prevention. We compared HIV disease parameters among women who seroconverted while receiving tenofovir-containing oral or vaginal pre-exposure prophylaxis (PrEP) to placebo. METHODS: Participants with HIV seroconversion in a randomized placebo-controlled trial of oral tenofovir, oral tenofovir/emtricitabine, and vaginal tenofovir gel (MTN-003) were followed in a longitudinal cohort study (MTN-015). The effect of oral and vaginal tenofovir-containing PrEP on HIV disease progression was compared to placebo using linear mixed effects and Cox proportional hazard models, as appropriate. Additional analyses were performed to compare the outcomes among participants with detectable tenofovir or emtricitabine in plasma at the first quarterly visit in MTN-003. RESULTS: A total of 224 participants were included in the analysis; 93% from South Africa and 94% clade C virus. No differences in HIV RNA at steady state or the trajectory over 12 months were observed for each active arm compared to placebo; tenofovir gel recipients had higher CD4+ T cell counts (722 vs 596 cells/mm3; p = 0.02) at 90 days after estimated HIV seroconversion and higher average rates of change over 12 months compared to placebo (-181 vs -92 cells/mm3 per year; p = 0.08). With a median follow-up of 31 months, no significant differences were observed for time to CD4+ T cell count ≤350 cells/mm3, or the composite endpoint of CD4+ T cells ≤350 cells/mm3, initiation of antiretroviral therapy or death for each active arm compared to placebo. Additionally, there were no significant differences in the HIV RNA or CD4+ T cell counts at baseline, the change to month 12, or any disease progression outcomes among participants with oral drug detected and no oral drug detected compared to placebo. CONCLUSIONS: No clinically significant differences in HIV seroconversion outcomes were observed among women randomized to tenofovir-containing oral or vaginal PrEP regimens, however low overall adherence limits the generalizability of these findings.

Brief Report: Dapivirine Vaginal Ring Use Does Not Diminish the Effectiveness of Hormonal Contraception.

OBJECTIVE: To evaluate the potential for a clinically relevant drug-drug interaction with concomitant use of a dapivirine vaginal ring, a novel antiretroviral-based HIV-1 prevention strategy, and hormonal contraception by examining contraceptive efficacies with and without dapivirine ring use. DESIGN: A secondary analysis of women participating in MTN-020/ASPIRE, a randomized, double-blind, placebo-controlled trial of the dapivirine vaginal ring for HIV-1 prevention. METHODS: Use of a highly effective method of contraception was an eligibility criterion for study participation. Urine pregnancy tests were performed monthly. Pregnancy incidence by arm was calculated separately for each hormonal contraceptive method and compared using an Andersen-Gill proportional hazards model stratified by site and censored at HIV-1 infection. RESULTS: Of 2629 women enrolled, 2310 women returned for follow-up and reported using a hormonal contraceptive method at any point during study participation (1139 in the dapivirine arm and 1171 in the placebo arm). Pregnancy incidence in the dapivirine arm versus placebo among women using injectable depot medroxyprogesterone acetate was 0.43% vs. 0.54%, among women using injectable norethisterone enanthate was 1.15% vs. 0%, among women using hormonal implants was 0.22% vs. 0.69%, and among women using oral contraceptive pills was 32.26% vs. 28.01%. Pregnancy incidence did not differ by study arm for any of the hormonal contraceptive methods. CONCLUSIONS: Use of the dapivirine ring does not reduce the effectiveness of hormonal contraceptives for pregnancy prevention. Oral contraceptive pill use was associated with high pregnancy incidence, potentially because of poor pill adherence. Injectable and implantable methods were highly effective in preventing pregnancy.

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 .).

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

INTRODUCTION: Women in sub-Saharan Africa are a priority population for evaluation of new biomedical HIV-1 prevention strategies. Antiretroviral pre-exposure prophylaxis is a promising prevention approach; however, clinical trials among young women using daily or coitally-dependent products have found low adherence. Antiretroviral-containing vaginal microbicide rings, which release medication over a month or longer, may reduce these adherence challenges. METHODS: ASPIRE (A Study to Prevent Infection with a Ring for Extended Use) is a phase III, randomized, double-blind, placebo-controlled trial testing the safety and effectiveness of a vaginal ring containing the non-nucleoside reverse transcriptase inhibitor dapivirine for prevention of HIV-1 infection. We describe the baseline characteristics of African women enrolled in the ASPIRE trial. RESULTS: Between August 2012 and June 2014, 5516 women were screened and 2629 HIV-1 seronegative women between 18-45 years of age were enrolled from 15 research sites in Malawi, South Africa, Uganda, and Zimbabwe. The median age was 26 years (IQR 22-31) and the majority (59%) were unmarried. Nearly 100% of participants reported having a primary sex partner in the prior three months but 43% did not know the HIV-1 status of their primary partner; 17% reported additional concurrent partners. Nearly two-thirds (64%) reported having disclosed to primary partners about planned vaginal ring use in the trial. Sexually transmitted infections were prevalent: 12% had Chlamydia trachomatis, 7% Trichomonas vaginalis, 4% Neisseria gonorrhoeae, and 1% syphilis. CONCLUSIONS: African HIV-1 seronegative women at risk of HIV -1 infection were successfully enrolled into a phase III trial of dapivirine vaginal ring for HIV-1 prevention.