927 research outputs found

    Antiretroviral prophylaxis: a defining moment in HIV control

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    A defining moment in the global AIDS response has been reached. The discourse is no longer about HIV prevention or HIV treatment; it is now about HIV control through the implementation of antiretrovirals as key components of combination interventions. Barely a year ago, visions of HIV control would have been considered far-fetched. The impetus for this change in mindset, which has been building since the XVIII International AIDS Conference in Vienna last year, emanates from the compelling evidence that antiretroviral drugs prevent HIV infection in the general heterosexual population, which is released this week and presented at the 6th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention in Rome by the Partners PrEP and Botswana TDF2 trials

    Access to Scientific Publications: The Scientist's Perspective

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    BACKGROUND: Scientific publishing is undergoing significant changes due to the growth of online publications, increases in the number of open access journals, and policies of funders and universities requiring authors to ensure that their publications become publicly accessible. Most studies of the impact of these changes have focused on the growth of articles available through open access or the number of open-access journals. Here, we investigated access to publications at a number of institutes and universities around the world, focusing on publications in HIV vaccine research--an area of biomedical research with special importance to the developing world. METHODS AND FINDINGS: We selected research papers in HIV vaccine research field, creating: 1) a first set of 50 most recently published papers with keywords "HIV vaccine" and 2) a second set of 200 articles randomly selected from those cited in the first set. Access to the majority (80%) of the recently published articles required subscription, while cited literature was much more accessible (67% freely available online). Subscriptions at a number of institutions around the world were assessed for providing access to subscription-only articles from the two sets. The access levels varied widely, ranging among institutions from 20% to 90%. Through the WHO-supported HINARI program, institutes in low-income countries had access comparable to that of institutes in the North. Finally, we examined the response rates for reprint requests sent to corresponding authors, a method commonly used before internet access became widespread. Contacting corresponding authors with requests for electronic copies of articles by email resulted in a 55-60% success rate, although in some cases it took up to 1.5 months to get a response. CONCLUSIONS: While research articles are increasingly available on the internet in open access format, institutional subscriptions continue to play an important role. However, subscriptions do not provide access to the full range of HIV vaccine research literature. Access to papers through subscriptions is complemented by a variety of other means, including emailing corresponding authors, joint affiliations, use of someone else's login information and posting requests on message boards. This complex picture makes it difficult to assess the real ability of scientists to access literature, but the observed differences in access levels between institutions suggest an unlevel playing field, in which some researchers have to spend more efforts than others to obtain the same information

    Declining HIV-1 Prevalence and Incidence among Police Officers - A potential Cohort for HIV Vaccine Trials, in Dar es Salaam, Tanzania.

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    A safe effective and affordable HIV vaccine is the most cost effective way to prevent HIV infection worldwide. Current studies of HIV prevalence and incidence are needed to determine potentially suitable cohorts for vaccine studies. The prevalence and incidence of HIV-1 infection among the police in Dar es Salaam in 1996 were 13.8% and 19.6/1000 PYAR respectively. This study aimed at determining the current prevalence and incidence of HIV in a police cohort 10 years after a similar study was conducted. Police officers in Dar es Salaam, Tanzania were prospectively enrolled into the study from 2005 and followed-up in an incidence study three years later. HIV infection was determined by two sequential enzyme linked immunosorbent assays (ELISAs) in the prevalence study and discordant results between two ELISAs were resolved by a Western blot assay. Rapid HIV assays (SD Bioline and Determine) were used for the incidence study. A total of 1,240 police participated in the HIV prevalence study from August 2005 to November 2008. Of these, 1101 joined the study from August 2005-September 2007 and an additional 139 were recruited between October 2007 to November 2008 while conducting the incidence study. A total of 726 (70%) out of the 1043 eligible police participated in the incidence study.The overall HIV-1 prevalence was 65/1240 (5.2%). Females had a non-statistically significant higher prevalence of HIV infection compared to males 19/253, (7.5%) vs. 46/987 (4.7%) respectively (p = 0.07). The overall incidence of HIV-1 was 8.4 per 1000 PYAR (95% CI 4.68-14.03), and by gender was 8.8 and 6.9 per 1000 PYAR, among males and females respectively, (p = 0.82). The HIV prevalence and incidence among the studied police has declined over the past 10 years, and therefore this cohort is better suited for phase I/II HIV vaccine studies than for efficacy trials

    Machine Learning Methods Enable Predictive Modeling of Antibody Feature:Function Relationships in RV144 Vaccinees

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    The adaptive immune response to vaccination or infection can lead to the production of specific antibodies to neutralize the pathogen or recruit innate immune effector cells for help. The non-neutralizing role of antibodies in stimulating effector cell responses may have been a key mechanism of the protection observed in the RV144 HIV vaccine trial. In an extensive investigation of a rich set of data collected from RV144 vaccine recipients, we here employ machine learning methods to identify and model associations between antibody features (IgG subclass and antigen specificity) and effector function activities (antibody dependent cellular phagocytosis, cellular cytotoxicity, and cytokine release). We demonstrate via cross-validation that classification and regression approaches can effectively use the antibody features to robustly predict qualitative and quantitative functional outcomes. This integration of antibody feature and function data within a machine learning framework provides a new, objective approach to discovering and assessing multivariate immune correlates.U.S. Military HIV Research ProgramCollaboration for AIDS Vaccine Discover (OPP1032817)National Institutes of Health (U.S.) (3R01AI080289-02S1)National Institutes of Health (U.S.) (5R01AI080289-03)United States. Army Medical Research and Materiel Command (National Institute of Allergy and Infectious Diseases (U.S.) Interagency Agreement Y1-AI-2642-12)Henry M. Jackson Foundation for the Advancement of Military Medicine (U.S.) (United States. Dept. of Defense Cooperative Agreement W81XWH-07-2-0067

    A Qualitative Study of Perceived Risk for HIV Transmission among Police Officers in Dar es Salaam, Tanzania.

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    Understanding people's views about HIV transmission by investigating a specific population may help to design effective HIV prevention strategies. In addition, knowing the inherent sexual practices of such a population, as well as the risky circumstances that may facilitate HIV transmission, is crucial for the said strategies to become effective. In this article, we report how police officers in Dar es Salaam, Tanzania, perceived the problem of HIV and AIDS in their local context, particularly in relation to unsafe sexual practices. The study was done with the view to recommending ways by which HIV transmission could be minimised within the police force. The study was conducted among members of the police force in Dar es Salaam, Tanzania. Eight focus group discussions (FGDs) were conducted, with a total of 66 participants who were mixed in terms of age, gender, and marital status. Some of these were caregivers to patients with AIDS. Data were analysed using the interpretive description approach. The participants believed that both individual sexual behaviour and work-related circumstances were sources of HIV infection. They also admitted that they were being tempted to engage in risky sexual practices because of the institutional rules that prohibit officers from getting married during their training and for three years after. Nevertheless, as members of the Police Force, they stressed the fact that the risky sexual behaviour that exposes them to HIV is not limited to the force; it is rather a common problem that is faced by the general population. However, they complained, the nature of their job exposes them to road accident victims, subjecting them further to possible infection, especially when they have to handle these road accident casualties without proper protective gear. Individual sexual behaviour and job-related circumstances are worth investigating if proper advice is to be given to the police regarding HIV prevention strategies. In order to improve the lives of these police officers, there is a need to review the existing institutional rules and practices to accommodate individual sexual needs. In addition, improving their working environment may minimize the risk of HIV transmission from handling casualties in emergency situations

    Willingness to participate in future HIV prevention studies among gay and bisexual men in Scotland, UK: a challenge for intervention trials

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    This article examines willingness to participate in future HIV prevention research among gay and bisexual men in Scotland, UK. Anonymous, self-complete questionnaires and Orasure Gäó oral fluid samples were collected in commercial gay venues. 1,320 men were eligible for inclusion. 78.2% reported willingness to participate in future HIV prevention research; 64.6% for an HIV vaccine, 57.4% for a behaviour change study, and 53.0% for a rectal microbicide. In multivariate analysis, for HIV vaccine research, greater age, minority ethnicity, and not providing an oral fluid sample were associated with lower willingness; heterosexual orientation and not providing an oral fluid sample were for microbicides; higher education and greater HIV treatment optimism were for behaviour change. STI testing remained associated with being more willing to participate in microbicide research and frequent gay scene use remained associated with being more willing to participate in behaviour change research. Having an STI in the past 12 months remained significantly associated with being willing to participate in all three study types. There were no associations between sexual risk behaviour and willingness. Although most men expressed willingness to participate in future research, recruitment of high-risk men, who have the potential to benefit most, is likely to be more challenging

    Targeting and Vaccine Durability Are Key for Population-level Impact and Cost-Effectiveness of a Pox-Protein HIV Vaccine Regimen in South Africa

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    Background: RV144 is to date the only HIV vaccine trial to demonstrate efficacy, albeit rapidly waning over time. The HVTN 702 trial is currently evaluating in South Africa a similar vaccine formulation to that of RV144 for subtype C HIV with additional boosters (pox-protein regimen). Using a detailed stochastic individual-based network model of disease transmission calibrated to the HIV epidemic, we investigate population-level impact and maximum cost of an HIV vaccine to remain cost-effective. Methods: Consistent with the original pox-protein regimen, we model a primary series of five vaccinations meeting the goal of 50% cumulative efficacy 24 months after the first dose and include twoyearly boosters that maintain durable efficacy over 10 years. We simulate vaccination programs in South Africa starting in 2027 under various vaccine targeting and HIV treatment and prevention assumptions. Results: Our analysis shows that this partially effective vaccine could prevent, at catch-up vaccination with 60% coverage, up to 941,000 (15.6%) new infections between 2027 and 2047 assuming current trends of antiretroviral treatment. An impact of up to 697,000 (11.5%) infections prevented could be achieved by targeting age cohorts of highest incidence. Economic evaluation indicates that, if treatment scale-up was achieved, vaccination could be cost-effective at a total cost of less than 385and385 and 62 per 10- year series (cost-effectiveness thresholds of 5,691and5,691 and 750). Conclusions: While a partially effective, rapidly waning vaccine could help to prevent HIV infections, it will not eliminate HIV as a public health priority in sub-Saharan Africa. Vaccination is expected to be most effective under targeted delivery to age groups of highest HIV incidence. Awaiting results of trial, the introduction of vaccination should go in parallel with continued innovation in HIV prevention, including studies to determine the costs of delivery and feasibility and further research into products with greater efficacy and durability
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