Gita Ramjee

Tenofovir-Based Preexposure Prophylaxis for HIV Infection among African Women

BACKGROUND Reproductive-age women need effective interventions to prevent the acquisition of human immunodeficiency virus type 1 (HIV-1) infection. METHODS We conducted a randomized, placebo-controlled trial to assess daily treatment with oral tenofovir disoproxil fumarate (TDF), oral tenofovir-emtricitabine (TDF-FTC), or 1% tenofovir (TFV) vaginal gel as preexposure prophylaxis against HIV-1 infection in women in South Africa, Uganda, and Zimbabwe. HIV-1 testing was performed monthly, and plasma TFV levels were assessed quarterly. RESULTS Of 12,320 women who were screened, 5029 were enrolled in the study. The rate of retention in the study was 91% during 5509 person-years of follow-up. A total of 312 HIV-1 infections occurred; the incidence of HIV-1 infection was 5.7 per 100 person-years. In the modified intention-to-treat analysis, the effectiveness was -49.0% with TDF (hazard ratio for infection, 1.49; 95% confidence interval [CI], 0.97 to 2.29), -4.4% with TDF-FTC (hazard ratio, 1.04; 95% CI, 0.73 to 1.49), and 14.5% with TFV gel (hazard ratio, 0.85; 95% CI, 0.61 to 1.21). In a random sample, TFV was detected in 30%, 29%, and 25% of available plasma samples from participants randomly assigned to receive TDF, TDF-FTC, and TFV gel, respectively. Independent predictors of TFV detection included being married, being older than 25 years of age, and being multiparous. Detection of TFV in plasma was negatively associated with characteristics predictive of HIV-1 acquisition. Elevations of serum creatinine levels were seen more frequently among participants randomly assigned to receive oral TDF-FTC than among those assigned to receive oral placebo (1.3% vs. 0.2%, P=0.004). We observed no significant differences in the frequencies of other adverse events. CONCLUSIONS None of the drug regimens we evaluated reduced the rates of HIV-1 acquisition in an intention-to-treat analysis. Adherence to study drugs was low. (Funded by the National Institutes of Health; VOICE ClinicalTrials.gov number, NCT00705679.).

Efficacy of Carraguard for prevention of HIV infection in women in South Africa: a randomised, double-blind, placebo-controlled trial

BACKGROUND Female-initiated HIV-prevention options, such as microbicides, are urgently needed. We assessed Carraguard, a carrageenan-based compound developed by the Population Council, for its efficacy and long-term safety in prevention of HIV infection in women. METHODS We undertook a randomised, placebo-controlled, double-blind trial in three South African sites in sexually-active, HIV-negative women, aged 16 years and older. 6202 participants, who were randomly assigned by a block randomisation scheme to Carraguard (n=3103) or placebo (methylcellulose [n=3099]), were instructed to use one applicator of gel plus a condom during each vaginal sex act. Participants were followed up for up to 2 years. Visits every 3 months included testing for HIV presence and pregnancy, pelvic examinations, risk reduction counselling, and treatment for curable sexually transmitted infections and symptomatic vaginal infections. The primary outcome was time to HIV seroconversion. Analysis was in the efficacy population (a subset of the intention-to-treat population, excluding participants for whom efficacy could not be assessed). This study is registered with ClinicalTrials.gov, number NCT00213083. FINDINGS For the primary outcome (time to HIV seroconversion) we analysed 3011 women in the Carraguard group and 2994 in the placebo group. HIV incidence was 3.3 per 100 woman-years (95% CI 2.8-3.9) in the Carraguard group (134 events) and 3.8 per 100 woman-years (95% CI 3.2-4.4) in the placebo group (151 events), with no significant difference in the distribution of time to seroconversion (p=0.30). The covariate-adjusted hazard ratio was 0.87 (95% CI 0.69-1.09). Rates of self-reported gel use (96.2% Carraguard, 95.9% placebo) and condom use (64.1% in both groups) at last sex acts were similar in both groups. On the basis of applicator testing, however, gel was estimated to have been used in only 42.1% of sex acts, on average (41.1% Carraguard, 43.1% placebo). 1420 (23%) women in the intention-to-treat population had adverse events (713 Carraguard, 707 placebo), and 95 (2%) women had adverse events that were related to gel use (48 Carraguard, 47 placebo). Serious adverse events occurred in 72 (2%) women in the Carraguard group and 78 (3%) in the placebo group, only one of which was considered possibly related to gel use (placebo group). INTERPRETATION This study did not show Carraguards efficacy in prevention of vaginal transmission of HIV. No safety concerns were recorded.

Lack of Effectiveness of Cellulose Sulfate Gel for the Prevention of Vaginal HIV Transmission

BACKGROUND Women make up more than 50% of adults living with human immunodeficiency virus (HIV) infection or the acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa. Thus, female-initiated HIV prevention methods are urgently needed. METHODS We performed a randomized, double-blind, placebo-controlled trial of cellulose sulfate, an HIV-entry inhibitor formulated as a vaginal gel, involving women at high risk for HIV infection at three African and two Indian sites. The primary end point was newly acquired infection with HIV type 1 or 2. The secondary end point was newly acquired gonococcal or chlamydial infection. The primary analysis was based on a log-rank test of no difference in the distribution of time to HIV infection, stratified according to site. RESULTS A total of 1398 women were enrolled and randomly assigned to receive cellulose sulfate gel (706 participants) or placebo (692 participants) and had follow-up HIV test data. There were 41 newly acquired HIV infections, 25 in the cellulose sulfate group and 16 in the placebo group, with an estimated hazard ratio of infection for the cellulose sulfate group of 1.61 (P=0.13). This result, which is not significant, is in contrast to the interim finding that led to the trial being stopped prematurely (hazard ratio, 2.02 [corrected]; P=0.05 [corrected]) and the suggestive result of a preplanned secondary (adherence-based) analysis (hazard ratio, 2.02; P=0.05). No significant effect of cellulose sulfate as compared with placebo was found on the risk of gonorrheal infection (hazard ratio, 1.10; 95% confidence interval [CI], 0.74 to 1.62) or chlamydial infection (hazard ratio, 0.71; 95% CI, 0.47 to 1.08). CONCLUSIONS Cellulose sulfate did not prevent HIV infection and may have increased the risk of HIV acquisition. (ClinicalTrials.gov number, NCT00153777; and Current Controlled Trials number, ISRCTN95638385.)

Diaphragm and lubricant gel for prevention of HIV acquisition in southern African women: a randomised controlled trial.

BACKGROUND Female-controlled methods of HIV prevention are urgently needed. We assessed the effect of provision of latex diaphragm, lubricant gel, and condoms (intervention), compared with condoms alone (control) on HIV seroincidence in women in South Africa and Zimbabwe. METHODS We did an open-label, randomised controlled trial in HIV-negative, sexually active women recruited from clinics and community-based organisations, who were followed up quarterly for 12-24 months (median 21 months). All participants received an HIV prevention package consisting of pre-test and post-test counselling about HIV and sexually transmitted infections, testing, treatment of curable sexually transmitted infections, and intensive risk-reduction counselling. The primary outcome was incident HIV infection. This study is registered with ClinicalTrials.gov, number NCT00121459. FINDINGS Overall HIV incidence was 4.0% per 100 woman-years: 4.1% in the intervention group (n=2472) and 3.9% in the control group (n=2476), corresponding to a relative hazard of 1.05 (95% CI 0.84-1.32, intention-to-treat analysis). The proportion of women using condoms was significantly lower in the intervention than in the control group (54%vs 85% of visits, p<0.0001). The proportions of participants who reported adverse events (60% [1523] vs 61% [1529]) and serious adverse events (5% [130] vs 4% [101]) were similar between the two groups. INTERPRETATION We observed no added protective benefit against HIV infection when the diaphragm and lubricant gel were provided in addition to condoms and a comprehensive HIV prevention package. Our observation that lower condom use in women provided with diaphragms did not result in increased infection merits further research. Although the intervention seemed safe, our findings do not support addition of the diaphragm to current HIV prevention strategies.

PRO2000 vaginal gel for prevention of HIV-1 infection (Microbicides Development Programme 301): a phase 3, randomised, double-blind, parallel-group trial

Summary Background Innovative prevention strategies for HIV-1 transmission are urgently needed. PRO2000 vaginal gel was efficacious against HIV-1 transmission in studies in macaques; we aimed to assess efficacy and safety of 2% and 0·5% PRO2000 gels against vaginal HIV-1 transmission in women in sub-Saharan Africa. Methods Microbicides Development Programme 301 was a phase 3, randomised, double-blind, parallel-group trial, undertaken at 13 clinics in South Africa, Tanzania, Uganda, and Zambia. We randomly assigned sexually active women, aged 18 years or older (≥16 years in Tanzania and Uganda) without HIV-1 infection in a 1:1:1 ratio to 2% PRO2000, 0·5% PRO2000, or placebo gel groups for 52 weeks (up to 104 weeks in Uganda). Randomisation was done by computerised random number generator. Investigators and participants were masked to group assignment. The primary efficacy outcome was incidence of HIV-1 infection before week 52, which was censored for pregnancy and excluded participants without HIV-1 follow-up data or with HIV-1 infection at enrolment. HIV-1 status was established by rapid tests or ELISA at screening at 12 weeks, 24 weeks, 40 weeks, and 52 weeks, and confirmed in a central reference laboratory. The primary safety endpoint was an adverse event of grade 3 or worse. Use of 2% PRO2000 gel was discontinued on Feb 14, 2008, on the recommendation of the Independent Data Monitoring Committee because of low probability of benefit. This trial is registered at http://isrctn.org, number ISRCTN 64716212. Findings We enrolled 9385 of 15 818 women screened. 2591 (95%) of 2734 participants enrolled to the 2% PRO2000 group, 3156 (95%) of 3326 in the 0·5% PRO2000 group, and 3112 (94%) of 3325 in the placebo group were included in the primary efficacy analysis. Mean reported gel use at last sex act was 89% (95% CI 86–91). HIV-1 incidence was much the same between groups at study end (incidence per 100 woman-years was 4·5 [95% CI 3·8–5·4] for 0·5% PRO2000 vs 4·3 [3·6–5·2] for placebo, hazard ratio 1·05 [0·82–1·34], p=0·71), and at discontinuation (4·7 [3·8–5·8] for 2% PRO2000 gel, 3·9 [3·0–4·9] for 0·5% PRO2000 gel, and 3·9 [3·1–5·0] for placebo gel). Incidence of the primary safety endpoint at study end was 4·6 per 100 woman-years (95% CI 3·9–5·4) in the 0·5% PRO2000 group and 3·9 (3·2–4·6) in the placebo group; and was 4·5 (3·7–5·5) in the 2% PRO2000 group at discontinuation. Interpretation Although safe, 0·5% PRO2000 and 2% PRO2000 are not efficacious against vaginal HIV-1 transmission and are not indicated for this use. Funding UK Department for International Development, UK Medical Research Council, European and Developing Countries Clinical Trials Partnership, International Partnership for Microbicides, and Endo Pharmaceuticals Solutions.

Safety and effectiveness of BufferGel and 0.5% PRO2000 gel for the prevention of HIV infection in women

Objective:To determine the safety and effectiveness of BufferGel and 0.5% PRO2000 microbicide gels for the prevention of male-to-female HIV transmission. Design:Phase II/IIb, randomized, placebo-controlled trial with three double-blinded gel arms and an open-label no gel arm. Methods:Study participants from Malawi, South Africa, Zambia, Zimbabwe, and the USA were instructed to apply study gel up to 1 h before each sex act and safety, sexual behavior, pregnancy, gel adherence, acceptability, and HIV serostatus were assessed during follow-up. Results:The 3101 enrolled women were followed for an average of 20.4 months with 93.6% retention and 81.1% self-reported gel adherence. Adverse event rates were similar in all study arms. HIV incidence rates in the 0.5% PRO2000 gel, BufferGel, placebo gel, and no gel arms were 2.70, 4.14, 3.91, and 4.02 per 100 women-years, respectively. HIV incidence in the 0.5% PRO2000 gel arm was lower than the placebo gel arm (hazard ratio = 0.7, P = 0.10) and the no gel arm (hazard ratio = 0.67, P = 0.06). HIV incidence rates were similar in the BufferGel and both placebo gel (hazard ratio = 1.10, P = 0.63) and no gel control arms (hazard ratio = 1.05, P = 0.78). HIV incidence was similar in the placebo gel and no gel arms (hazard ratio = 0.97, P = 0.89). Conclusion:The 0.5% PRO2000 gel demonstrated a modest 30% reduction in HIV acquisition in women. However, these results were not statistically significant and subsequent findings from the Microbicide Development Programme (MDP) 301 trial have confirmed that 0.5% PRO2000 gel has little or no protective effect. BufferGel did not alter the risk of HIV infection. Both products were well tolerated.

Prevalence of HIV among truck drivers visiting sex workers in KwaZulu-Natal, South Africa.

Background Although the role of mobile populations in the spread of HIV has been documented in several countries, there are few data on HIV among truck drivers in South Africa and the sex workers with whom they interact. Goal To determine HIV prevalence and risk behavior in a sample of truck drivers visiting commercial sex workers at truck stops. Study Design Two sex workers from each of five truck stops were trained to obtain informed consent, administer questionnaires to obtain data on demographic and migration patterns, and collect saliva samples for HIV testing from their clients. Data on HIV prevalence and demographic characteristics of sex workers operating at the truck stops were obtained from an ongoing vaginal microbicide trial. Results The mean age of the truck drivers (all men) was 37 years (range, 18–71 years), and that of the sex workers (all females) was 25 years (range, 15–49 years). Sixty-six percent of the men reported having a sexually transmitted infection in the previous six months, and 37% always stopped for sex along the route. Twenty-nine percent reported never using condoms with sex workers, whereas 13% had used condoms with their wives. All men traveled to more than one province in South Africa, and 65% traveled to neighboring countries. Anal sex was practiced by 42% of the men. The overall HIV prevalence (in the two groups combined) was 56%. Conclusion Truck drivers may have facilitated the spread of HIV infection throughout southern Africa.

Short-course antiretroviral therapy in primary HIV infection.

BACKGROUND Short-course antiretroviral therapy (ART) in primary human immunodeficiency virus (HIV) infection may delay disease progression but has not been adequately evaluated. METHODS We randomly assigned adults with primary HIV infection to ART for 48 weeks, ART for 12 weeks, or no ART (standard of care), with treatment initiated within 6 months after seroconversion. The primary end point was a CD4+ count of less than 350 cells per cubic millimeter or long-term ART initiation. RESULTS A total of 366 participants (60% men) underwent randomization to 48-week ART (123 participants), 12-week ART (120), or standard care (123), with an average follow-up of 4.2 years. The primary end point was reached in 50% of the 48-week ART group, as compared with 61% in each of the 12-week ART and standard-care groups. The average hazard ratio was 0.63 (95% confidence interval [CI], 0.45 to 0.90; P=0.01) for 48-week ART as compared with standard care and was 0.93 (95% CI, 0.67 to 1.29; P=0.67) for 12-week ART as compared with standard care. The proportion of participants who had a CD4+ count of less than 350 cells per cubic millimeter was 28% in the 48-week ART group, 40% in the 12-week group, and 40% in the standard-care group. Corresponding values for long-term ART initiation were 22%, 21%, and 22%. The median time to the primary end point was 65 weeks (95% CI, 17 to 114) longer with 48-week ART than with standard care. Post hoc analysis identified a trend toward a greater interval between ART initiation and the primary end point the closer that ART was initiated to estimated seroconversion (P=0.09), and 48-week ART conferred a reduction in the HIV RNA level of 0.44 log(10) copies per milliliter (95% CI, 0.25 to 0.64) 36 weeks after the completion of short-course therapy. There were no significant between-group differences in the incidence of the acquired immunodeficiency syndrome, death, or serious adverse events. CONCLUSIONS A 48-week course of ART in patients with primary HIV infection delayed disease progression, although not significantly longer than the duration of the treatment. There was no evidence of adverse effects of ART interruption on the clinical outcome. (Funded by the Wellcome Trust; SPARTAC Controlled-Trials.com number, ISRCTN76742797, and EudraCT number, 2004-000446-20.).

Characterization and Selection of HIV-1 Subtype C Isolates for Use in Vaccine Development

HIV-1 genetic diversity among circulating strains presents a major challenge for HIV-1 vaccine development, particularly for developing countries where less sequence information is available. To identify representative viruses for inclusion in candidate vaccines targeted for South Africa, we applied an efficient sequence survey strategy to samples from recently and chronically infected persons residing in potential vaccine trial sites. All 111 sequences were subtype C, including 30 partial gag, 26 partial pol, 27 V2-V3 env, and 28 V5-partial gp41 sequences. Of the 10 viruses cultured from recently infected individuals, 9 were R5 and 1 was R5X4. Two isolates, Du151 and Du422, collected within 2 months of infection, were selected as vaccine strains on the basis of their amino acid similarity to a derived South African consensus sequence The selection of recently transmitted R5 isolates for vaccine design may provide an advantage in a subtype C R5-dominant epidemic. The full-length Du422 gag and Du151 pol and env genes were cloned into the Venezuelan equine encephalitis (VEE) replicon particle (VRP) expression system. Du422 Gag protein expressed from the VRP accumulated to a high level and was immunogenic as demonstrated by cytotoxic T lymphocyte responses in mice vaccinated with gag-VRPs. Optimization of codon use for VRP expression in human cells did not enhance expression of the gag gene. The cloned Du151 env gene encoded a functional protein as demonstrated by fusion of VRP-infected cells with cells expressing CD4 and CCR5. Genes identified in this study have been incorporated into the VEE VRP candidate vaccines targeted for clinical trial in South Africa.

Incidence of HIV-1 Dual Infection and Its Association with Increased Viral Load Set Point in a Cohort of HIV-1 Subtype C-Infected Female Sex Workers

This longitudinal study aimed to determine the incidence and pathogenic implications of dual human immunodeficiency virus type 1 (HIV-1) infection in a cohort of female sex workers. Blood samples from 31 recently infected women were screened by use of a heteroduplex mobility assay and sequencing. The median viral load set point was 5404 copies/mL (n=22), which was measured by use of the bDNA assay. Within 3 months of infection, 19% (6/31) of the women were dually infected with 2 distinct HIV-1 subtype C viruses. No evidence of superinfection was detected over the course of 24 months of follow-up, indicating that the risk of dual infection is highest around the time of the initial infection. There was a significant association between dual infection and elevated viral load set point.