Centre For The AIDS Programme Of Research In South Africa Research Articles

Extended safety and tolerability of subcutaneous CAP256V2LS and VRC07-523LS in HIV-negative women: study protocol for the randomised, placebo-controlled double-blinded, phase 2 CAPRISA 012C trial

IntroductionWomen-controlled HIV prevention technologies that overcome adherence challenges of available daily oral pre-exposure prophylaxis and give women a choice of options are urgently needed. Broadly neutralising monoclonal antibodies (bnAbs) administered...

Research training experience of Vietnamese health sciences undergraduates visiting the Centre for the AIDS Programme of Research in South Africa.

The Centre for the AIDS Programme of Research in South Africa (CAPRISA), performs world-leading research on the epidemiology, pathogenesis, prevention and treatment of HIV/AIDS, tuberculosis, and - more recently - COVID-19. A rigorous yet supportive academic culture has nurtured the careers of many successful health sciences researchers, some of whom have worked for the organization since its inception over 20 years ago. This focus on professional development is founded on a training programme that invests heavily in the individual with the payoff of strengthening the science base for HIV and tuberculosis research in South Africa. Those selected for mentorship are typically medical students from the University of KwaZulu-Natal, adjoining the headquarters of CAPRISA in Durban. Increasingly, however, the institute attracts international fellows from partnering organizations to experience the intellectually demanding, scientifically robust, cutting-edge research environment. The purpose of this voices piece is to narrate and critically evaluate the experience from the dual perspectives of host and visitor of a research training programme undertaken by three undergraduate health sciences students from Vietnam, enrolled at VinUniversity. This was the inaugural running of what is expected to be an annual summer trip to CAPRISA by Hanoi-based medical and nursing students. The formative educational experience in best practice tackling of infectious diseases in challenging clinical contexts demonstrated the importance of investing in research placement programmes for public health impact. The exchange has inspired each student to become a future leader in seeking bold, innovative, and strategic approaches to improve global health issues in their home country.

Non-Lactobacillus-Dominant and Polymicrobial Vaginal Microbiomes Are More Common in Younger South African Women and Predictive of Increased Risk of Human Immunodeficiency Virus Acquisition.

Adolescent girls and young women aged 15‒24 years in sub-Saharan Africa are at disproportionate risk of human immunodeficiency virus (HIV) infection. Given the known association between vaginal microbial dysbiosis and HIV susceptibility, we performed an age-stratified analysis of the vaginal microbiome in South African women and compared this to their risk of HIV acquisition. Vaginal microbiome data were generated by mass spectrometry-based proteomic analysis of cervicovaginal lavages collected from participants (n = 688) in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial. Participants were grouped by age (18-19 years, n = 93; 20-24 years, n = 326; 25-41 years, n = 269). Four microbiome types were identified based on predominant taxa, including Lactobacillus crispatus (CST-LC, 12.2%), Lactobacillus iners (CST-LI, 43.6%), Gardnerella vaginalis (CST-GV, 26.6%), or polymicrobial (CST-PM, 15.1%). Women aged 18-19 and 20-24 years had increased CST-PM and a non-Lactobacillus-dominant microbiome compared to those 25-41 years (odds ratio [OR], 3.14 [95% confidence interval {CI}, 1.12-7.87], P = .017; OR, 2.81 [95% CI, 1.07-7.09], P = .038, respectively; and OR, 1.65 [95% CI, 1.02-2.65], P = .028; OR, 1.40 [95% CI, 1.01-1.95], P = .030, respectively). The HIV incidence rate of women with CST-PM microbiome was 7.19-fold higher compared to women with CST-LC (hazard ratio [HR], 7.19 [95% CI, 2.11-24.5], P = .00162), which was also consistent in women aged 20-24 years (HR, 4.90 [95% CI, 1.10-21.9], P = .0375). Younger women were more likely to have a higher-risk polymicrobial microbiome suggesting that vaginal microbiota are contributing to increased HIV-1 susceptibility in this group. NCT00441298.

Using joint models to study the association between CD4 count and the risk of death in TB/HIV data

BackgroundThe association structure linking the longitudinal and survival sub-models is of fundamental importance in the joint modeling framework and the choice of this structure should be made based on the clinical background of the study. However, this information may not always be accessible and rationale for selecting this association structure has received relatively little attention in the literature. To this end, we aim to explore four alternative functional forms of the association structure between the CD4 count and the risk of death and provide rationale for selecting the optimal association structure for our data. We also aim to compare the results obtained from the joint model to those obtained from the time-varying Cox model.MethodsWe used data from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) AIDS Treatment programme, the Starting Antiretroviral Therapy at Three Points in Tuberculosis (SAPiT) study, an open-label, three armed randomised, controlled trial between June 2005 and July 2010 (N=642). In our analysis, we combined the early and late integrated arms and compared results to the sequential arm. We utilized the Deviance Information Criterion (DIC) to select the final model with the best structure, with smaller values indicating better model adjustments to the data.ResultsPatient characteristics were similar across the study arms. Combined integrated therapy arms had a reduction of 55% in mortality (HR:0.45, 95% CI:0.28-0.72) compared to the sequential therapy arm. The joint model with a cumulative effects functional form was chosen as the best association structure. In particular, our joint model found that the area under the longitudinal profile of CD4 count was strongly associated with a 21% reduction in mortality (HR:0.79, 95% CI:0.72-0.86). Where as results from the time-varying Cox model showed a 19% reduction in mortality (HR:0.81, 95% CI:0.77-0.84).ConclusionsIn this paper we have shown that the “current value” association structure is not always the best structure that expresses the correct relationship between the outcomes in all settings, which is why it is crucial to explore alternative clinically meaningful association structures that links the longitudinal and survival processes.

Joint modelling of longitudinal and time-to-event data: an illustration using CD4 count and mortality in a cohort of patients initiated on antiretroviral therapy

BackgroundModelling of longitudinal biomarkers and time-to-event data are important to monitor disease progression. However, these two variables are traditionally analyzed separately or time-varying Cox models are used. The former strategy fails to recognize the shared random-effects from the two processes while the latter assumes that longitudinal biomarkers are exogenous covariates, resulting in inefficient or biased estimates for the time-to-event model. Therefore, we used joint modelling for longitudinal and time-to-event data to assess the effect of longitudinal CD4 count on mortality.MethodsWe studied 4014 patients from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) who initiated ART between June 2004 and August 2013. We used proportional hazards regression model to assess the effect of baseline characteristics (excluding CD4 count) on mortality, and linear mixed effect models to evaluate the effect of baseline characteristics on the CD4 count evolution over time. Thereafter, the two analytical approaches were amalgamated to form an advanced joint model for studying the effect of longitudinal CD4 count on mortality. To illustrate the virtues of the joint model, the results from the joint model were compared to those from the time-varying Cox model.ResultsUsing joint modelling, we found that lower CD4 count over time was associated with a 1.3-fold increase in the risk of death, (HR: 1.34, 95% CI: 1.27-1.42). Whereas, results from the time-varying Cox model showed lower CD4 count over time was associated with a 1.2-fold increase in the risk of death, (HR: 1.17, 95% CI: 1.12-1.23).ConclusionsJoint modelling enabled the assessment of the effect of longitudinal CD4 count on mortality while correcting for shared random effects between longitudinal and time-to-event models. In the era of universal test and treat, the evaluation of CD4 count is still crucial for guiding the initiation and discontinuation of opportunistic infections prophylaxis and assessment of late presenting patients. CD4 count can also be used when immunological failure is suspected as we have shown that it is associated with mortality.

Integrated provision of topical pre-exposure prophylaxis in routine family planning services in South Africa: a non-inferiority randomized controlled trial.

IntroductionTenofovir‐containing oral pre‐exposure prophylaxis (PrEP) is recommended for those at substantial risk as part of combination HIV prevention. However, there are limited data, beyond clinical trial settings, to guide the introduction of PrEP in healthcare services with adequate levels of adherence. Since young women in Africa are at high risk of HIV and likely to utilize family planning (FP) services, the feasibility, acceptability and effectiveness of integrating topical PrEP provision into routine FP services was assessed.MethodsThis two‐arm, randomized controlled, non‐inferiority, open‐label extension trial was undertaken in urban and rural KwaZulu‐Natal, South Africa. HIV‐negative eligible women (n = 372) from the parent trial (Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004) were randomized to receive tenofovir gel either through intervention (FP clinics, n = 189) or control clinics (CAPRISA research clinics, n = 183). Non‐inferiority was predefined as gel use in the intervention clinics would be no more than 20% lower than in the control clinics. Adherence, retention and HIV incidence rates were assessed.ResultsWomen were enrolled between November 2012 and October 2014, and followed up for 682.3 women‐years (mean = 22 months). Baseline characteristics of women in intervention and control clinics were comparable and retention rates were 92.1% and 92.3% respectively. Women in intervention clinics and control clinics returned on average 5.2 (95% confidence interval (CI): 4.7 to 5.7) and 5.7 (CI: 5.2 to 6.2) used gel applicators per month respectively, with a mean difference of −0.47 (CI: −1.16 to 0.21). Per‐protocol estimates were on average 5.5 (CI: 5.0 to 6.1) and 5.8 (CI: 5.3 to 6.3) respectively, with a mean difference of −0.25 (CI: −0.98 to 0.48), meeting the non‐inferiority criteria. Adherence, based on proportion of reported sex acts covered by two gel doses, was 79.9% (CI: 76.7 to 83.2) in intervention compared with 73.9% (CI: 70.7 to 77.1) in control clinics; mean difference:6.0% (CI: 1.5 to 10.6) (p = 0.009). HIV incidence rates were 3.5 (CI: 1.8 to 6.0) and 3.6 (CI: 1.9 to 6.3) per 100 women‐years in intervention and control clinics respectively. Both these incidence rates were lower than the age‐standardized rate of 6.2 per 100 women‐years (n = 444) in the placebo arm of the parent trial (p = 0.019).ConclusionsProvision of topical PrEP as part of an integrated FP service achieved higher adherence, and was as feasible, acceptable and effective in preventing HIV as provision through a research setting. This provides useful evidence for scale‐up of oral PrEP in urban and rural high burden communities.

Frequency of Hepatitis B Virus Resistance Mutations in Women Using Tenofovir Gel as Pre-Exposure Prophylaxis.

Intermittent use of a single antiretroviral agent in the presence of a replicating virus could potentially increase the development of antiviral resistance. The pericoital, before-and-after sex, dosing regimen used in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 tenofovir gel trial meant that women who were infected with hepatitis B virus (HBV) were exposed intermittently to tenofovir during their participation. The impact of this dosing regimen on HBV resistance was assessed by amplification of the HBV polymerase region from 37 stored plasma samples of women who were HBV surface antigen positive. All samples belonged to HBV genotype A. None of the known tenofovir resistance mutations (M240V/I, L180M, A194T, V214A, N238T) were identified in any individuals. While it is reassuring that no resistance mutations were found among women using topical tenofovir, the rapidly expanding access to oral tenofovir-containing HIV pre-exposure prophylaxis (PrEP), with higher systemic exposure to the drug, makes monitoring for potential HBV drug resistance important.

Covariate random effects on the CD4 count variation during HIV disease progression in women.

Purpose: To investigate the variation in CD4 count between HIV positive patients due to clinical covariates at each phase of the HIV disease progression.Patients and methods: The Centre for the AIDS Programme of Research in South Africa (CAPRISA) conducted different studies in which female patients were initially enrolled in HIV negative cohorts (phase 1). Seroconverts were further followed-up weekly to fortnightly visits up to 3 months (phase 2: acute infection), monthly visits from 3 to 12 months (phase 3: early infection), quarterly visits thereafter (phase 4: established infection) until antiretroviral therapy (ART) initiation (phase 5).Results: Eighteen out of the 46 CD4 count covariates investigated were significant. Low average CD4 counts at acute and early phase entry improved at a faster rate than entries at higher average CD4 count. During therapy, all the 18 covariates induced significantly different patients’ average CD4 counts. The rate of change of CD4 count greatly varied in response to lactate dehydrogenase during the acute phase. Red blood cells increase resulted in the patients’ CD4 counts approaching a common higher level during the early phase. During therapy, the already high CD4 counts improved faster than lower ones in response to the red blood cells increase. As the monocytes increased, patients with lower average CD4 counts became worse than those with higher average CD4 counts.Conclusion: Changes in the covariates measurements either induced no variation effects in certain phases or improved the CD4 count at a faster rate for those patients whose average CD4 was already high or worsen the CD4 level which was already low or caused the patients’ CD4 counts to approach the same level – higher or lower than the general cohort. The studied covariates induced wide variations in the CD4 count between HIV positive patients during the ART phase.

An Evaluation to Determine the Strongest CD4 Count Covariates during HIV Disease Progression in Women in South Africa.

IntroductionPast endeavours to deal with the obstacle of expensive Cluster of Difference 4 (CD4+) count diagnostics in resource-limited settings have left a long trail of suggested continuous CD4+ count clinical covariates that turned out to be a potentially important integral part of the human immunodeficiency virus (HIV) treatment process during disease progression. However, an evaluation to determine the strongest candidates among these CD4+ count covariates has not been well documented.MethodsThe Centre for the AIDS Programme of Research in South Africa (CAPRISA) initially enrolled HIV-negative (phase 1) patients into different study cohorts. The patients who seroconverted (237) during follow-up care were enrolled again into a post-HIV infection cohort where they were further followed up with weekly to fortnightly visits up to 3 months (phase 2: acute infection), monthly visits from 3–12 months (phase 3: early infection) and quarterly visits thereafter (phase 4: established infection) until antiretroviral therapy (ART) initiation (phase 5). The CD4+ count and 46 covariates were repeatedly measured at each phase of the HIV disease progression. A multilevel partial least squares approach was applied as a variable reduction technique to determine the strongest CD4+ count covariates.ResultsOnly 18 of the 46 investigated clinical attributes were the strongest CD4+ count covariates and the top 8 were positively and independently associated with the CD4+ count. Besides the confirmatory lymphocytes, these were basophils, albumin, haematocrit, alkaline phosphatase (ALP), mean corpuscular volume (MCV), platelets, potassium and monocytes. Overall, electrolytes, proteins and red blood cells were the dominant categories for the strongest covariates.ConclusionOnly a few of the many previously suggested continuous CD4+ count clinical covariates showed the potential to become an important integral part of the treatment process. Prolonging the pre-treatment period of the HIV disease progression by effectively incorporating and managing the covariates for long-term influence on the CD4+ cell response has the potential to delay challenges associated with ART side effects.Electronic supplementary materialThe online version of this article (10.1007/s40121-019-0235-4) contains supplementary material, which is available to authorized users.

Association of Polymorphisms in the Regulatory Region of the Cyclophilin a Gene (PPIA) with Gene Expression and HIV/AIDS Disease Progression.

Human cyclophilin A (CypA) encoded by peptidyl prolyl isomerase A gene (PPIA), enhances HIV-1 replication by aiding capsid uncoating. The association of genetic variation in the PPIA regulatory region with susceptibility to HIV-1 infection, disease progression, and gene expression among black South Africans at risk for infection or infected with HIV-1 is unknown. We genotyped 539 participants from 2 longitudinal study cohorts of black South Africans at high risk for infection or infected with HIV-1 for PPIA regulatory single nucleotide polymorphisms by polymerase chain reaction-restriction fragment length polymorphism. Minor allele (G) of SNP rs6850 (rs6850 G) significantly associated with higher viral loads (mean 4.85 versus 4.46 log copies/mL, P = 0.0006) and lower CD4 T-cell counts (mean 506 versus 557 cells/μL, P = 0.0256) during the acute phase of infection in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 002 cohort. Consistently, rs6850 G significantly associated with higher viral loads (mean 4.49 versus 4.01 log copies/mL, P < 0.0001) and lower CD4 T-cell counts (mean 442 versus 494 cells/μL, P = 0.0002) during the early chronic phase of infection in the CAPRISA 002 cohort; rs6850 G further associated significantly with rapid CD4 T-cell decline in the CAPRISA 002 cohort (P = 0.0481) and Sinikithemba chronic infection cohort (P = 0.0156). Interestingly, rs6850 G significantly associated with elevated CypA mRNA levels in HIV-1-positive individuals (P = 0.0061). These data suggest that rs6850 G enhances HIV-1 replication through upregulation of CypA expression following HIV-1 infection. The data support ongoing efforts to develop anti-HIV-1 drugs that block interaction of HIV-1 and cellular proteins.

Tenofovir Gel for the Prevention of Herpes Simplex Virus Type 2 Infection

BackgroundGlobally, herpes simplex virus type 2 (HSV-2) infection is the most common cause of genital ulcer disease. Effective prevention strategies for HSV-2 infection are needed to achieve the goals of the World Health Organization global strategy for the prevention and control of sexually transmitted infections.MethodsWe assessed the effectiveness of pericoital tenofovir gel, an antiviral microbicide, in preventing HSV-2 acquisition in a subgroup of 422 HSV-2–negative women enrolled in the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 study, a double-blind, randomized, placebo-controlled trial. Incident HSV-2 cases were identified by evidence of seroconversion on an HSV-2 IgG enzyme-linked immunosorbent assay between study enrollment and exit. A confirmatory analysis was performed by Western blot testing.ResultsThe HSV-2 incidence rate was 10.2 cases per 100 person-years (95% confidence interval [CI], 6.8 to 14.7) among 202 women assigned to tenofovir gel, as compared with 21.0 cases per 100 person-years (95% CI, 16.0 to 27.2) among 222 women assigned to placebo gel (incidence rate ratio, 0.49; 95% CI, 0.30 to 0.77; P=0.003). The HSV-2 incidence rate among the 25 women with vaginal tenofovir concentrations of 10,000 ng per milliliter or more was 5.7 cases per 100 person-years, as compared with 15.5 cases per 100 person-years among the 103 women with no detectable vaginal tenofovir (incidence rate ratio, 0.37; 95% CI, 0.04 to 1.51; P=0.14). As confirmed by Western blot testing, there were 16 HSV-2 seroconversions among women assigned to tenofovir gel as compared with 36 among those assigned to the placebo gel (incidence rate ratio, 0.45; 95% CI, 0.23 to 0.82; P=0.005).ConclusionsIn this study in South Africa, pericoital application of tenofovir gel reduced HSV-2 acquisition in women. (Funded by the U.S. Agency for International Development and others; ClinicalTrials.gov number, NCT00441298.)

Ability to develop broadly neutralizing HIV-1 antibodies is not restricted by the germline Ig gene repertoire.

The human Ig repertoire is vast, producing billions of unique Abs from a limited number of germline Ig genes. The IgH V region (IGHV) is central to Ag binding and consists of 48 functional genes. In this study, we analyzed whether HIV-1-infected individuals who develop broadly neutralizing Abs show a distinctive germline IGHV profile. Using both 454 and Illumina technologies, we sequenced the IGHV repertoire of 28 HIV-infected South African women from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 002 and 004 cohorts, 13 of whom developed broadly neutralizing Abs. Of the 259 IGHV alleles identified in this study, approximately half were not found in the International Immunogenetics Database (IMGT). This included 85 entirely novel alleles and 38 alleles that matched rearranged sequences in non-IMGT databases. Analysis of the rearranged H chain V region genes of mAbs isolated from seven of these women, as well as previously isolated broadly neutralizing Abs from other donors, provided evidence that at least eight novel or non-IMGT alleles contributed to functional Abs. Importantly, we found that, despite a wide range in the number of IGHV alleles in each individual, including alleles used by known broadly neutralizing Abs, there were no significant differences in germline IGHV repertoires between individuals who do and do not develop broadly neutralizing Abs. This study reports novel IGHV repertoires and highlights the importance of a fully comprehensive Ig database for germline gene usage prediction. Furthermore, these data suggest a lack of genetic bias in broadly neutralizing Ab development in HIV-1 infection, with positive implications for HIV vaccine design.

Assessing the implementation effectiveness and safety of 1% tenofovir gel provision through family planning services in KwaZulu-Natal, South Africa: study protocol for an open-label randomized controlled trial.

BackgroundThe Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 trial demonstrated a 39% reduction in HIV infection, with a 54% HIV reduction in women who used tenofovir gel consistently. A confirmatory trial is expected to report results in early 2015. In the interim, we have a unique window of opportunity to prepare for and devise effective strategies for the future policy and programmatic scale-up of tenofovir gel provision. One approach is to integrate tenofovir gel provision into family planning (FP) services. The CAPRISA 008 implementation trial provides an opportunity to provide post-trial access to tenofovir gel while generating empiric evidence to assess whether integrating tenofovir gel provision into routine FP services can achieve similar levels of adherence as the CAPRISA 004 trial.Methods/designThis is a two-arm, open-label, randomized controlled non-inferiority trial. A maximum of 700 sexually active, HIV-uninfected women aged 18 years and older who previously participated in an antiretroviral prevention study will be enrolled from an urban and rural site in KwaZulu-Natal, South Africa. The anticipated study duration is 30 months, with active accrual requiring approximately 12 months (following which an open cohort will be maintained) and follow-up continuing for approximately 18 months. At each of the two sites, eligible participants will be randomly assigned to receive tenofovir gel through either FP services (intervention arm) or through the CAPRISA research clinics (control arm). As part of the study intervention, a quality improvement approach will be used to assist the FP services to expand their current services to include tenofovir gel provision.DiscussionThis protocol aims to address an important implementation question on whether FP services are able to effectively incorporate tenofovir gel provision for this at-risk group of women in South Africa. Provision of tenofovir gel to the women from the CAPRISA 004 trial meets the ethical obligation for post-trial access, and helps identify a potential avenue for future scale-up of microbicides within the public health system of South Africa.Trial registrationThis trial was registered with the South Africa Department of Health (reference: DOH-27-0812-4129) and ClinicalTrials.gov (reference: NCT01691768) on 05 July 2012.

Differences in HIV type 1 neutralization breadth in 2 geographically distinct cohorts in Africa.

To investigate whether distinct populations have differing human immunodeficiency virus type 1 (HIV) neutralizing antibody responses, we compared 20 women from Tanzania's HIV Superinfection Study (HISIS) cohort, who were infected multiple HIV subtypes, and 22 women from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) cohort, who were infected exclusively with HIV subtype C. By 2 years after infection, 35% of HISIS subjects developed neutralization breadth, compared with 9% of CAPRISA subjects (P = .0131). Cumulative viral loads between 3 and 12 months were higher in the HISIS group (P = .046) and strongly associated with breadth (P < .0001). While viral load was the strongest predictor, other factors may play a role, as the odds of developing breadth remained higher in HISIS even after correction for viral load.

Implementation of adolescent-friendly voluntary medical male circumcision using a school based recruitment program in rural KwaZulu-Natal, South Africa.

BackgroundEpidemiological data from South Africa demonstrate that risk of human immunodeficiency virus (HIV) infection in males increases dramatically after adolescence. Targeting adolescent HIV-negative males may be an efficient and cost-effective means of maximising the established HIV prevention benefits of voluntary medical male circumcision (VMMC) in high HIV prevalence–, low circumcision practice–settings. This study assessed the feasibility of recruiting male high school students for VMMC in such a setting in rural KwaZulu-Natal.Methods and FindingsFollowing community and key stakeholder consultations on the acceptability of VMMC recruitment through schools, information and awareness raising sessions were held in 42 high schools in Vulindlela. A three-phase VMMC demand-creation strategy was implemented in partnership with a local non-governmental organization, ZimnadiZonke, that involved: (i) community consultation and engagement; (ii) in-school VMMC awareness sessions and centralized HIV counselling and testing (HCT) service access; and (iii) peer recruitment and decentralized HCT service access. Transport was provided for volunteers to the Centre for the AIDS Programme of Research in South Africa (CAPRISA) clinic where the forceps-guided VMMC procedure was performed on consenting HIV-negative males. HIV infected volunteers were referred to further care either at the CAPRISA clinic or at public sector clinics. Between March 2011 and February 2013, a total of 5165 circumcisions were performed, the majority (71%) in males aged between 15 and 19 years. Demand-creation strategies were associated with an over five-fold increase in VMMC uptake from an average of 58 procedures/month in initial community engagement phases, to an average of 308 procedures/month on initiation of the peer recruitment–decentralized service phase. Post-operative adverse events were rare (1.2%), mostly minor and self-resolving.ConclusionsOptimizing a high volume, adolescent-targeted VMMC program was feasible, acceptable and safe in this setting. Adaptive demand-creation strategies are required to sustain high uptake.

Developmental pathway for potent V1V2-directed HIV-neutralizing antibodies

Antibodies capable of neutralizing HIV-1 often target variable regions 1 and 2 (V1V2) of the HIV-1 envelope, but the mechanism of their elicitation has been unclear. Here we define the developmental pathway by which such antibodies are generated and acquire the requisite molecular characteristics for neutralization. Twelve somatically related neutralizing antibodies (CAP256-VRC26.01-12) were isolated from donor CAP256 (from the Centre for the AIDS Programme of Research in South Africa (CAPRISA)); each antibody contained the protruding tyrosine-sulphated, anionic antigen-binding loop (complementarity-determining region (CDR) H3) characteristic of this category of antibodies. Their unmutated ancestor emerged between weeks 30-38 post-infection with a 35-residue CDR H3, and neutralized the virus that superinfected this individual 15 weeks after initial infection. Improved neutralization breadth and potency occurred by week 59 with modest affinity maturation, and was preceded by extensive diversification of the virus population. HIV-1 V1V2-directed neutralizing antibodies can thus develop relatively rapidly through initial selection of B cells with a long CDR H3, and limited subsequent somatic hypermutation. These data provide important insights relevant to HIV-1 vaccine development.

Limited HIV-1 Superinfection in Seroconverters from the CAPRISA 004 Microbicide Trial

HIV-1 superinfection (SI) occurs when an infected individual acquires a distinct new viral strain. The rate of superinfection may be reflective of the underlying HIV risk in a population. The Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004 clinical trial demonstrated that women who used a tenofovir-containing microbicide gel had lower rates of HIV infection than women using a placebo gel. Women who contracted HIV-1 during the trial were screened for the occurrence of superinfection by next-generation sequencing of the viral gag and env genes. There were two cases (one in each trial arm) of subtype C superinfection identified from the 76 women with primary infection screened at two time points (rate of superinfection, 1.5/100 person-years). Both women experienced a >0.5-log increase in viral load during the window when superinfection occurred. The rate of superinfection was significantly lower than the overall primary HIV incidence in the microbicide trial (incidence rate ratio [IRR], 0.20; P=0.003). The women who seroconverted during the trial reported a significant increase in sexual contact with their stable partner 4 months after seroconversion (P<0.001), which may have lowered the risk of superinfection in this population. The lower frequency of SI compared to the primary incidence is in contrast to a report from a general heterosexual African population but agrees with a study of high-risk women in Kenya. A better understanding of the rate of HIV superinfection could have important implications for ongoing HIV vaccine research.

Suboptimal awareness and comprehension of published preexposure prophylaxis efficacy results among physicians in Massachusetts

In 2010, the centre for the AIDS Programme of Research in South Africa (CAPRISA)004 and iPrEx trials (microbicide gel containing tenofovir and oral pill containing tenofovir–emtricitabine, respectively) demonstrated that antiretroviral preexposure prophylaxis (PrEP) reduced the risk of HIV acquisition among high-risk individuals. To determine the facilitators and barriers to PrEP provision by health-care providers, we conducted an online, quantitative survey of Massachusetts-area physicians following the publication of the CAPRISA and iPrEx results. We assessed awareness and comprehension of efficacy data, prescribing experience, and anticipated provision of oral and topical PrEP among physicians, as well as demographic and behavioral factors associated with PrEP awareness and prescribing intentions. The majority of HIV specialists and generalist physicians were aware of data from these PrEP trials and able to correctly interpret the results, however, correct interpretation of findings tended to vary according to specialty (i.e., HIV specialists had greater awareness than generalists). In addition, provider concerns regarding PrEP efficacy and safety, as well its ability to divert funds from other HIV prevention resources, were associated with decreased intentions to prescribe both oral and topical PrEP. Findings suggest that a substantial proportion of physicians who may have contact with at-risk individuals may benefit from interventions that provide accurate data on the risks and benefits of PrEP in order to facilitate effective PrEP discussions with their patients. Future studies to develop and test interventions aimed at health-care providers should be prioritized to optimize implementation of PrEP in clinical settings.

Safety of Tenofovir Gel, a Vaginal Microbicide, in South African Women: Results of the Caprisa 004 Trial

Tenofovir gel, used vaginally before and after coitus, reduced women's acquisition of HIV by 39%. This is a safety assessment of tenofovir gel, including renal, bone, gastrointestinal, genital and haematological parameters. In the Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004, a double-blind, randomized placebo-controlled trial, 445 of the 889 eligibly enrolled women were assigned to tenofovir gel. All participants were advised to use the gel vaginally only, with one dose of gel within 12 h before and a second dose as soon as possible after sex, with no more than two doses in 24 h. Clinical and laboratory safety data were collected at monthly and quarterly visits, respectively. Genital assessments were undertaken at enrolment and quarterly thereafter, or as indicated. Women assigned to tenofovir gel were exposed to an average monthly vaginal dose of 240 mg of tenofovir (six applications). In total, six women, three in each group, had mild creatinine elevations, all of which occurred in July/August 2008. The incidence of anaemia was 3.5 and 3.8 per 100 women-years in tenofovir and placebo groups, respectively (P=0.80). Of the six women (four tenofovir and two placebo) experiencing bone fractures, none were associated with abnormal phosphate or calcium values. The proportion of women with diarrhoea was higher in the tenofovir gel group (17% versus 11%; P=0.026). There was no significant increase of any genital adverse event in the tenofovir group. No significant renal, haematological, genital or bone effects were associated with the use of tenofovir gel. Aside from a puzzling increase in diarrhoea, tenofovir gel has an excellent safety profile.

Adherence support approaches in biomedical HIV prevention trials: experiences, insights and future directions from four multisite prevention trials.

Adherence is a critical component of the success of antiretroviral-based pre-exposure prophylaxis (PrEP) in averting new HIV-infections. Ensuring drug availability at the time of potential HIV exposure relies on self-directed product use. A deeper understanding of how to best support sustained PrEP adherence remains critical to current and future PrEP efforts. This paper provides a succinct synthesis of the adherence support experiences from four pivotal PrEP trials—Centre for the AIDS Programme of Research in South Africa (CAPRISA) 004, FEM-PrEP, Iniciativa Prophylaxis (iPrEx), and Vaginal and Oral Interventions to Control the Epidemic (VOICE). Notwithstanding variability in the design, population/cohort, formulation, drug, dosing strategy, and operationalization of adherence approaches utilized in each trial, the theoretical basis and experiences in implementation and monitoring of the approaches used by these trials provide key lessons for optimizing adherence in future research and programmatic scale-up of PrEP. Recommendations from across these trials include participant-centered approaches, separating measurement of adherence from adherence counseling, incorporating tailored strategies that go beyond education, fostering motivation, and addressing the specific context in which an individual incorporates and negotiates PrEP use.