Future HIV Prevention Trials Research Articles

High HIV incidence among young women in South Africa: Data from a large prospective study.

IntroductionSouth Africa has the highest national burden of HIV globally. Understanding drivers of HIV acquisition in recently completed, prospective studies in which HIV was an endpoint may help inform the strategy and investments in national HIV prevention efforts and guide the design of future HIV prevention trials. We assessed HIV incidence and correlates of incidence among women enrolled in ECHO (Evidence for Contraceptive Options and HIV Outcomes), a large, open-label randomized clinical trial that compared three highly effective. reversible methods of contraception and rates of HIV acquisition.MethodsDuring December 2015 to October 2018, ECHO followed sexually active, HIV-seronegative women, aged 16–35 years, seeking contraceptive services and willing to be randomized to one of three contraceptive methods (intramuscular depot medroxyprogesterone acetate, copper intrauterine device, or levonorgestrel implant) for 12–18 months at nine sites in South Africa. HIV incidence based on prospectively observed HIV seroconversion events. Cox proportional hazards regression models were used to define baseline cofactors related to incident HIV infection.Results5768 women were enrolled and contributed 7647 woman-years of follow-up. The median age was 23 years and 62.5% were ≤24 years. A total of 345 incident HIV infections occurred, an incidence of 4.51 per 100 woman-years (95%CI 4.05–5.01). Incidence was >3 per 100 woman-years at all sites. Age ≤24 years, baseline infection with sexually transmitted infections, BMI≤30, and having new or multiple partners in the three months prior to enrollment were associated with incident HIV.ConclusionsHIV incidence was high among South African women seeking contraceptive services. Integration of diagnostic management of sexually transmitted infections alongside delivery of HIV prevention options in health facilities providing contraception services are needed to mitigate ongoing risks of HIV acquisition for this vulnerable population.Clinical trial registrationClinicalTrials.gov, number NCT02550067 was the main Clinical Trial from which this secondary, non-randomized / observational analysis was derived with data limited to just South African sites.

Risk Factors for HIV Seroconversion in a High Incidence Cohort of Men Who Have Sex with Men and Transgender Women in Bangkok, Thailand

Background: In order to assess feasibility for future HIV prevention trials, we measured HIV incidence, retention, and assessed risk factors for seroconversion among men who have sex with men (MSM) and transgender women (TGW) in Bangkok, Thailand between 2017-2019. Methods: We conducted an 18-month prospective cohort study of HIV-uninfected Thai cisgender men and transgender women who reported sex with men in the past six months. HIV and syphilis testing and computer-based behavioral questionnaires were administered at each visit. We utilized Poisson regression to calculate HIV incidence rates. A survival random forest model identified the most predictive risk factors for HIV seroconversion and then used in a survival regression tree model to elucidate hazard ratios for individuals with groups of selected risk factors. Cox proportional hazards (PH) regression evaluated the strength of association between individual covariates and risk of seroconversion. Findings: From April 2017-October 2019, 1,184 participants were screened, 167 were found ineligible, and 1,017 enrolled. Over the 18-month study, visit retention was 93·4% (95% CI 91·6%-94·8%) and HIV incidence was 3·73 per 100 person-years (95% CI 2·79-5·87). Utilizing survival regression tree modeling, those who were 18-20 years of age, reported sexual attraction to mostly or only men, and had five or more lifetime sexual partners were 4·9 times more likely to seroconvert compared to other cohort participants. Factors associated with HIV incidence utilizing Cox PH regression included sexual attraction to mostly or only men (adjusted hazard ratio (aHR) 14·9 (95% CI 20·1-107·9), younger age (18-19 years, aHR 10·88 (95% CI 4·12-28·7), five or greater lifetime sexual partners (aHR 2·0, 95%CI 1·1-3·6), inconsistent condom use with casual partners (aHR 2·43, 95% CI 1·3-4·5), and prior HIV testing (adjusted HR 2·0, 95% CI 1·1-3·5). Interpretation: HIV incidence remains high among Bangkok-based MSM and TGW. These key populations have high retention and are ideal candidates for efficacy evaluation of future prevention strategies. Funding Statement: This work was supported by the US Army Medical Research and Materiel Command (Military Infectious Diseases Research Program) (cooperative agreements W81XWH-11-2-0174 and W81XWH-07-2-0067 with the Henry M. Jackson Foundation for the Advancement of Military Medicine), the US Army Medical Materiel Development Activity, and the National Institute of Allergy and Infectious Disease (interagency agreement Y1-AI-2642-12 with the US Army Medical Research and Materiel Command) and the Division of AIDS Interagency Agreements (DAIDS IAA Y1-AI-2642-16). Declaration of Interests: T.C. reports grants from U.S. Army, grants from NIH, M.R. and S.V. reports grants from US Army Medical Research and Materiel Command with Henry M. Jackson Foundation for the Advancement of Military Medicine, during the conduct of the study. All other authors report no potential conflicts. Ethics Approval Statement: The study was reviewed and approved by the institutional review boards at Walter Reed Army Institute of Research (WRAIR), Faculty of Tropical Medicine at Mahidol University, and the Royal Thai Army. All participants provided written informed consent prior to enrollment.

Use of reliable contraceptives and its correlates among women participating in Simulated HIV vaccine efficacy trials in key-populations in Uganda

To prevent pregnancy in trials, reliable contraceptive use is key. We investigated reliable contraceptive use at baseline and six months in key-populations in Uganda, during two Simulated HIV Vaccine Efficacy trials (SiVETs). SiVETs were nested within observational cohorts of Fisherfolk (2012–2014) and Female sex workers (2014–2017). Women in the observational cohorts were screened and enrolled into the SiVET. The trial administered a licensed Hepatitis B vaccine at 0, 1 and 6 months. Contraceptive use data were recorded at baseline and follow-up clinic visits. Reliable contraceptives (injectable Depot Medroxyprogesterone Acetate (DMPA), implant, pills, and intrauterine device (IUD)) were promoted and provided to women not using a reliable method at enrolment. Overall, 367 women were enrolled. At baseline 203 (55%) reported use of reliable contraceptive. Of the 164 women not using a reliable method at enrolment, 131 (80%) started using them during follow-up bringing the overall number to 334 (91%) at the end of follow-up. Young age (≤35 years) was an independent predictor of reliable contraceptive use at both time points while other factors varied. Promotion and provision of reliable contraceptives increased the proportion using them and could help reduce the risk of pregnancy in future HIV prevention trials.

Recruitment of Female Sex Workers in HIV Prevention Trials: Can Efficacy Endpoints Be Reached More Efficiently?

Randomized controlled trials (RCTs) of HIV biomedical prevention interventions often enroll participants with varying levels of HIV exposure, including people never exposed to HIV. We assessed whether enrolling larger proportion of participants with consistently high exposure to HIV, such as female sex workers (FSWs), might reduce trial duration and improve the accuracy of product efficacy estimates in future HIV prevention trials. We used an individual-based stochastic model to simulate event-driven RCTs of an HIV prevention intervention providing 80% reduction in susceptibility per act under different proportions of FSW enrolled. A 5% annual dropout rate was assumed for both FSW and non-FSW in our main scenario, but rates of up to 50% for FSW were also explored. Enrolling 20% and 50% FSW reduced the median-simulated trial duration from 30 months with 0% FSW enrolled to 22 months and 17 months, respectively. Estimated efficacy increased from 71% for RCTs without FSW to 74% and 76% for RCTs with 20% and 50% FSW enrolled, respectively. Increasing the FSW dropout rate to 50% increased the duration of RCTs by 1-2 months on average and preserved the gain in estimated efficacy. Despite the potential logistical challenges of recruiting and retaining FSW, trialists should revisit the idea of enrolling FSW in settings where HIV incidence among FSW is higher than among non-FSW. Our analysis suggests that enrolling FSW would increase HIV incidence, reduce trial duration, and improve efficacy estimates, even if the annual dropout rate among FSW participants is high.

Contextualizing willingness to participate: recommendations for engagement, recruitment & enrolment of Kenyan MSM in future HIV prevention trials

BackgroundThe HIV epidemic among men who have sex with men (MSM) continues to expand globally. The addition of an efficacious, prophylactic vaccine to combination prevention offers immense hope, particularly in low- and middle- income countries which bear the greatest global impact. However, in these settings, there is a paucity of vaccine preparedness studies that specifically pertain to MSM. Our study is the first vaccine preparedness study among MSM and female sex workers (FSWs) in Kenya. In this paper, we explore willingness of Kenyan MSM to participate in HIV vaccine efficacy trials. In addition to individual and socio-cultural motivators and barriers that influence willingness to participate (WTP), we explore the associations or linkages that participants draw between their experiences with or knowledge of medical research both generally and within the context of HIV/AIDS, their perceptions of a future HIV vaccine and their willingness to participate in HIV vaccine trials.MethodsUsing a social network-based approach, we employed snowball sampling to recruit MSM into the study from Kisumu, Mombasa, and Nairobi. A field team consisting of seven community researchers conducted in-depth interviews with a total of 70 study participants. A coding scheme for transcribed and translated data was developed and the data was then analysed thematically.ResultsMost participants felt that an HIV vaccine would bring a number of benefits to self, as well as to MSM communities, including quelling personal fears related to HIV acquisition and reducing/eliminating stigma and discrimination shouldered by their community. Willingness to participate in HIV vaccine efficacy trials was highly motivated by various forms of altruism. Specific researcher responsibilities centred on safe-guarding the rights and well-being of participants were also found to govern WTP, as were reflections on the acceptability of a future preventive HIV vaccine.ConclusionStrategies for engagement of communities and recruitment of trial volunteers for HIV vaccine efficacy trials should not only be grounded in and informed by investigations into individual and socio-cultural factors that impact WTP, but also by explorations of participants’ existing experiences with or knowledge of medical research as well as attitudes and acceptance towards a future HIV vaccine.

Accuracy of Self-Report and Pill-Count Measures of Adherence in the FEM-PrEP Clinical Trial: Implications for Future HIV-Prevention Trials

Accuracy of Self-Report and Pill-Count Measures of Adherence in the FEM-PrEP Clinical Trial: Implications for Future HIV-Prevention Trials

Willingness to participate in future HIV prevention trials in Beira, Mozambique

In preparation for trials of new HIV prevention methods, willingness to participate (WTP) was assessed in Beira, Mozambique. A totla of 1 019 women participating in an HIV incidence study, and 97 men participating in a separate WTP survey, were interviewed. When comparing the answers to questions that were identical in the two studies, WTP was higher among women than men for all prevention methods. Among women, WTP was highest for trials evaluating daily oral pre-exposure prophylaxis (PrEP; 84.4% reporting very likely to participate), followed by vaccination (77.8%), daily vaginal gel use (67.7%), coital vaginal gel use (67.1%) and monthly vaginal ring use (47.7%). Among men, WTP was highest for trials evaluating vaccination (57.6%), followed by daily vaginal gel use for female sexual partners (52.5%), daily oral PrEP (49.5%), coital vaginal gel use for female sexual partners (46.4%) and monthly vaginal ring use for female sexual partners (39.4%). Among men, the most important motivators for trial participation were social benefits, whereas personal risks (most notably receiving injections and/or blood draws) were deterrents; this was not assessed in women. Other important lessons learnt are that male circumcision and antiretroviral drugs were not generally recognised as ways to prevent HIV, that having to use hormonal contraception during trial participation will likely reduce WTP, and that evening clinics are not likely to be popular. The barriers reported in this and other studies may be challenging but are not impossible to overcome.

'I heard about this study on the radio': using community radio to strengthen Good Participatory Practice in HIV prevention trials.

BackgroundDuring the Microbicides Development Program (MDP) 301, a clinical trial of a candidate microbicide amongst women in Johannesburg, South Africa, we used community radio to promote awareness of the trial, to inform community members about specific medical research procedures and terminologies, and to stimulate dialogue between researchers and local citizens.MethodsWe used mixed methods to undertake a retrospective analysis of the social responses to the radio shows, focusing specifically on recruitment and participation in the MDP301 trial. We collected quantitative data that describes the themes and listener responses, the costs per broadcast, and the impact of the radio broadcasts on trial recruitment. Qualitative data on local reactions to the shows was gleaned from in-depth interviews with trial participants.ResultsOver a seven-year period, 205 individual broadcasts were made on two separate community radio stations. Show themes were either specifically related to medical research issues (36%), or focused on general health issues (46%), and sexual and reproductive health, including HIV prevention (18%). 403 listeners made telephone calls to the radio station, and 12% of women enrolled as participants in MDP301 (n = 9, 385) reported that they had first heard about the trial from the radio. Qualitative interviews (n = 401) with female MDP301 participants highlighted the effects of the radio shows in making women aware of the trial, impressing them with the importance of health screening and knowledge, legitimizing trial participation, and stimulating dialogue between trial participants and their male partners.ConclusionsCommunity radio is a potent tool for raising awareness and local knowledge about medical research and, in addition to other methodologies, can be used to promote recruitment into clinical trials. We suggest that future HIV prevention trials consider an investment in community radio beyond recruitment advertisements that incorporates this into the broader community engagement plan as a key element of Good Participatory Practice in clinical trial settings.

Accuracy of Self-Report and Pill-Count Measures of Adherence in the FEM-PrEP Clinical Trial: Implications for Future HIV-Prevention Trials.

Oral emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) has been evaluated as pre-exposure prophylaxis (PrEP). We describe the accuracy of self-reported adherence to FTC/TDF and pill counts when compared to drug concentrations in the FEM-PrEP trial. Using drug concentrations of plasma tenofovir (TFV) and intracellular tenofovir diphosphate (TFVdp) among a random sub-sample of 150 participants assigned to FTC/TDF, we estimated the positive predictive value (PPV) of four adherence measures. We also assessed factors associated with misreporting of adherence using multiple drug-concentration thresholds and explored pill use and misreporting using semi-structured interviews (SSIs). Reporting use of ≥1 pill in the previous 7 days had the highest PPV, while pill-count data consistent with missing ≤1 day had the lowest PPV. However, all four measures demonstrated poor PPV. Reported use of oral contraceptives (OR 2.26; p = 0.014) and weeks of time in the study (OR 1.02; p < 0.001) were significantly associated with misreporting adherence. Although most SSI participants said they did not misreport adherence, participant-dependent adherence measures were clearly unreliable in the FEM-PrEP trial. Pharmacokinetic monitoring remains the measure of choice until more reliable participant-dependent measures are developed.

Women's Perspectives on Female-Initiated Barrier Methods for the Prevention of HIV in the Context of Methamphetamine Use and Partner Violence

BackgroundFemale-initiated barrier methods for the prevention of HIV may be an effective alternative for drug-using women who are unable to negotiate safe sex, often as a result of physical and/or sexual partner violence. MethodsUtilizing a SAVA (substance abuse, violence, and AIDS) syndemic framework, we qualitatively examined perspectives on female condoms and vaginal microbicides among 18 women with histories of methamphetamine abuse and partner violence in San Diego, California. FindingsMost women were not interested in female condoms owing to perceived discomfort, difficulty of insertion, time-intensive effort, and unappealing appearance. Alternatively, most women viewed vaginal microbicides as a useful method. Positive aspects included convenience, ability to disguise as a lubricant, and a sense of control and empowerment. Concerns included possible side effects, timing of application, and unfavorable characteristics of the gel. Acceptability of female-initiated barrier methods was context dependent (i.e., partner type, level of drug use and violence that characterized the sexual relationship). ConclusionsFindings indicate that efforts are needed to address barriers identified for vaginal microbicides to increase its uptake in future HIV prevention trials and marketing of future Food and Drug Administration-approved products. Strategies should address gender-based inequalities (e.g., partner violence) experienced by drug-using women and promote female empowerment. Education on female-initiated barrier methods is also needed for women who use drugs, as well as health care providers and other professionals providing sexual health care and contraception to women with histories of drug use and partner violence.

Is preexposure prophylaxis ready for prime time use in HIV prevention research?

Is preexposure prophylaxis ready for prime time use in HIV prevention research?

Willingness to participate in HIV vaccine efficacy trials among high risk men and women from fishing communities along Lake Victoria in Uganda

IntroductionHIV vaccine efficacy trials conducted in suitable populations are anticipated in sub-Saharan Africa. We assessed the willingness to participate in future vaccine trials among individuals from fishing communities along Lake Victoria, Uganda. MethodsFrom July to October 2012, we described a hypothetical vaccine trial to 328 (62.2% men) adults (18–49 years), at risk of HIV infection within 6 months of enrolment in a cohort and assessed their willingness to participate in the trial. Chi-square and logistic regression models were fitted to assess associations between vaccine trial attributes, participants’ characteristics and willingness to participate. ResultsOverall, 99.4% expressed willingness to participate in the hypothetical HIV vaccine trial. This decreased marginally with introduction of particular vaccine trial attributes. Delaying pregnancy for 10 months and large blood draw had the largest effects on reducing willingness to participate to 93.5% (p=0.02) and 94.5% (p=0.01) respectively. All the vaccine trial attributes in combination reduced willingness to participate to 90.6%. This overall reduction in willingness to participate was significantly associated with gender and exchange of gifts for sex in multivariable analysis; women were more than three times as likely to have expressed unwillingness to participate in future vaccine trials as men (aOR=3.4, 95% CI: 1.55, 7.33) and participants who never received gifts in exchange for sex were more than four times as likely to have expressed unwillingness as those who received gifts for sex (aOR=4.5; 95%CI 1.30, 16.70). The main motivators of participation were access to HIV counselling and testing services (31.9%), HIV education (18.0%), hope of being prevented from acquiring HIV (16.6%) and health care (12.5%). ConclusionOur study identifies an important population for inclusion in future HIV prevention trials and provides important insights into acceptability of trial procedures, differences in decisions of women and men and areas for further participant education.

The epidemiology of HIV and HSV-2 infections among women participating in microbicide and vaccine feasibility studies in Northern Tanzania.

ObjectivesTo prepare for future HIV prevention trials, we conducted prospective cohort studies among women working in food and recreational facilities in northern Tanzania. We examined the prevalence and incidence of HIV and HSV-2, and associated risk factors.MethodsWomen aged 18–44 years working in food and recreational facilities were screened to determine their eligibility for the studies. Between 2008–2010, HIV-negative women were enrolled and followed for 12 months. At enrolment and 3-monthly, we collected socio-demographic and behavioural data, and performed clinical examinations for collection of biological specimens that were tested for reproductive tract infections. Risk factors for HIV and HSV-2 incidence were investigated using Poisson regression models.ResultsWe screened 2,229 and enrolled 1,378 women. The median age was 27 years (interquartile range, IQR 22, 33), and median duration working at current facility was 2 years. The prevalences of HIV at screening and HSV-2 at enrolment were 16% and 67%, respectively. Attendance at the 12-month visit was 86%. HIV and HSV-2 incidence rates were 3.7 (95% confidence interval, CI: 2.8,5.1) and 28.6 (95% CI: 23.5,35.0)/100 person-years, respectively. Women who were separated, divorced, or widowed were at increased risk of HIV (adjusted incidence rate ratio, aRR = 6.63; 95% CI: 1.97,22.2) and HSV-2 (aRR = 2.00; 95% CI: 1.15,3.47) compared with married women. Women reporting ≥3 partners in the past 3 months were at higher HIV risk compared with women with 0–1 partner (aRR = 4.75; 95% CI: 2.10,10.8), while those who had reached secondary education or above were at lower risk of HSV-2 compared with women with incomplete primary education (aRR = 0.42; 95% CI: 0.22,0.82).ConclusionsHIV and HSV-2 rates remain substantially higher in this cohort than in the general population, indicating urgent need for effective interventions. These studies demonstrate the feasibility of conducting trials to test new interventions in this highly-mobile population.

Preparing for HIV Vaccine Trials in Nigeria: Building the Capacity of the Community and National Coordinating, Regulatory and Ethical Bodies

Background: There is paucity of high-level clinical trials in Nigeria for several reasons, which include: lack of trained investigators and mentorship in the implementation of Clinical trials at international standard; inadequate investment and trained regulatory agencies to provide oversight. Therefore, the need for capacity of the national coordinating agencies (NCA); the investigative team, supporting research laboratory and the community to be developed in preparation for future HIV prevention trials including vaccine trials. Method: In collaboration with the University of Ottawa, three regulatory agencies (NAFDAC -National Agency for Food and Drug Administration Control, NHREC- National Health Research Ethics Committee and NACA-National Agency for Control of AIDS) were identified for capacity building. We developed a phase IIB mock clinical trial model for the purpose of capacity building which created a platform for hands-on training alongside mentoring, meetings, site base visits with full community engagement. Result: Eight trainees from NACA, NHREC, NAFDAC and the investigative team completed biostatistics and epidemiology course; three trainees attended a Clinical Trial course at the Institute of Human Virology Nigeria and had additional 2-day training/mentoring at the University of Ottawa and thereafter these trainees conducted a 2-day site assessment of the ongoing sero-discordant study in Jos, Nigeria with full community engagement. A trained research team is a member of the national HIV vaccine plan implementation committee and the supporting research laboratory has updated all standard operating manuals for ISO15198 accreditation. Conclusion: Sustained interaction/integration through trainings/mentorship of National Coordinating Agencies and investigative team promotes commitment relevant for building in-country capacity for successful HIV vaccine clinical trial. An on-going vaccine preparedness HIV sero-discordant couple’s cohort is being used to apply principles and concepts of this structure and the trainings in preparation for future HIV prevention including vaccine trials.

Design challenges facing clinical trials of the effectiveness of new HIV-prevention technologies

Recent successes of antiretroviral pre-exposure prophylaxis (PrEP) in preventing HIV infection have raised questions whether further placebo controlled trials of new HIVprevention technologies are ethically justifiable. A trial with active agent(s) in the comparator group can be designed either as a superiority or non-inferiority trial. In a non-inferiority trial the hypothesis tested is that the intervention is not inferior to, by a predefined clinically relevant amount, or at least as effective as, the comparator. Noninferiority trials pose challenges in data interpretation. Firstly it is possible to show equivalence of two non-effective interventions. If the active comparator intervention is ineffective, the new intervention would be shown to be noninferior to this inactive intervention, while neither intervention is superior to placebo or no intervention. The second challenge is that any effect that dilutes the true efficacy of an intervention in a trial, such as non-adherence, loss to follow-up or protocol violations, makes it easier for the two interventions to be declared equivalent. Nondifferential low adherence is unlikely to lead to the conclusion that an inferior intervention is non-inferior. However, differential adherence between study arms, which is more likely in non-blinded trials, is likely to bias the results and lead to incorrect conclusions. Investigators conducting non-inferiority trials will have to pay special attention to supporting, measuring and maintaining high adherence. The goal in future noninferiority trials should be to maintain similar levels of high adherence in all study arms, but at a minimum to reduce the likelihood of differential adherence across study arms. 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins AIDS 2012, 26:000‐000

Identifying At-Risk Populations in Kenya and South Africa

To identify and describe populations at risk for HIV in 3 clinical research centers in Kenya and South Africa. Prospective cohort study. Volunteers reporting recent sexual activity, multiple partners, transactional sex, sex with an HIV-positive partner, or, if male, sex with men (MSM; in Kenya only) were enrolled. Sexually active minors were enrolled in South Africa only. Risk behavior, HIV testing, and clinical data were obtained at follow-up visits. From 2005 to 2008, 3023 volunteers were screened, 2113 enrolled, and 1834 contributed data on HIV incidence. MSM had the highest HIV incidence rate of 6.8 cases per 100 person-years [95% confidence interval (CI): 4.9 to 9.2] followed by women in Kilifi and Cape Town (2.7 cases per 100 person-years, 95% CI: 1.7 to 4.2). No seroconversions were observed in Nairobi women or men in Nairobi or Cape Town who were not MSM. In 327 MSM, predictors of HIV acquisition included report of genital ulcer (Hazard Ratio: 4.5, 95% CI: 1.7 to 11.6), not completing secondary school education (HR: 3.4, 95% CI: 1.6 to 7.2) and reporting receptive anal intercourse (HR: 8.2, 95% CI: 2.7 to 25.0). Paying for sex was inversely associated with HIV infection (HR: 0.2, 95% CI: 0.04 to 0.8). 279 (13.0%) volunteers did not return after the first visit; subsequent attrition rates ranged from 10.4 to 21.8 volunteers per 100 person-years across clinical research centers. Finding, enrolling, and retaining risk populations for HIV prevention trials is challenging in Africa. African MSM are not frequently engaged for research, have high HIV incidence, need urgent risk reduction counseling, and may represent a suitable population for future HIV prevention trials.

Willingness to Participate in Biomedical HIV Prevention Studies After the HVTN 503/Phambili Trial: A Survey Conducted Among Adolescents in Soweto, South Africa

Adolescents may be appropriate for inclusion in biomedical HIV prevention trials. Adolescents' overall willingness to participate (WTP) in biomedical HIV prevention trials was examined, including after the prematurely discontinued phase IIb HVTN 503/Phambili HIV vaccine trial, in Soweto, South Africa. An interview-administered cross-sectional survey was conducted among 506 adolescents (16-18 years) between October 2008 and March 2009. The assessment included WTP in HIV prevention trials, sexual and substance use behavior, and related psychosocial constructs. Multivariate logistic regression analyses examined predictors of WTP in biomedical prevention trials. The sample primarily consisted of female participants (n = 298, 59%), and 50% of all participants were sexually active. WTP in general was high (93%), with 75% WTP in a vaccine trial after being informed about the HVTN 503/Phambili trial. Less exposure to stressors [odds ratio (OR): 2.8, confidence interval (CI): 1.3 to 6.3] was associated with adolescents' WTP in HIV biomedical prevention trials overall. Those with less exposure to stressors (OR: 1.7, CI: 1.1 to 2.8) and not sexually active (OR: 2.1, CI: 1.4 to 3.3) were predictive of WTP after the HVTN 503/Phambili trial. A higher number of sexual partners were associated with unwillingness to participate more generally (P = 0.039) and specifically after the HIV vaccine trial (P = 0.0004). The high level of adolescents' WTP in biomedical prevention trials is encouraging, especially after the prematurely discontinued HVTN 503/Phambili HIV vaccine trial. High-risk youth were less likely to be WTP, although those not yet sexually active were more WTP. Future biomedical HIV prevention trials should address challenges to enrollment of high-risk adolescents who may show less WTP.

HIV Incidence, Risk Factors, and Motivation for Biomedical Intervention among Gay, Bisexual Men, and Transgender Persons in Northern Thailand

BackgroundHIV prevalence among men who have sex with men (MSM) and transgender (TG) persons is high and increasing in Chiang Mai, northern Thailand.ObjectivesTo describe demographic, socioeconomic, sexual behavior and interest in future HIV prevention trials among gay and bisexual MSM and TG presenting for HIV testing (VCT) and pre-screening for the iPrEx pre-exposure chemoprophylaxis trail.MethodsIn 2008–09, MSM/TG participants attending VCT were interviewed and tested for HIV and STI. Univariate and multivariate regression analyses were done to assess associations with HIV infection.ResultsA total of 551 MSM clients (56.1% gay, 25.4% TG, and 18.5% bisexual (BS)) were enrolled. The mean age was 23.9 years. HIV prevalence among MSM overall was 12.9% (71/551); 16.5% among gay men, 9.3% among TG, and 6.9% among BS. Consistent use of condom was low, 33.3% in insertive anal sex and 31.9% in receptive anal sex. Interest in participation was high, 86.3% for PrEP, 69.7% for HIV vaccine trials, but 29.9% for circumcision. HIV was independently associated with being gay identified, aOR 2.8, p = 0.037 and with being aged 25–29, aOR 2.7, p = 0.027. Among repeat testers, HIV incidence was 8.2/100 PY, 95% CI, 3.7/100PY to 18.3/100PY.ConclusionHIV risks and rates varied by self-reported sexual orientation and gender identity. HIV was associated with sexual practices, age, and being gay-identified. These are populations are in need of novel prevention strategies and willing to participate in prevention research.

P1-S6.45 Impact of a community level, diffusion based HIV/STI intervention on heterosexually-identified, socially marginalised men in urban, coastal Peru

ObjectivesThe NIMH Collaborative HIV/STD Intervention Trial implemented a 2-year intervention based on the theory of diffusion of innovations to decrease unprotected sex with non-primary partners among high-risk populations including heterosexually-identified,...

The challenge of defining standards of prevention in HIV prevention trials

As new HIV prevention tools are developed, researchers face a number of ethical and logistic questions about how and when to include novel HIV prevention strategies and tools in the...