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Phylodynamics of HIV-1 from a phase III AIDS vaccine trial in Bangkok, Thailand.

ABSTRACT: In 2003, a phase III placebo-controlled trial (VAX003) was completed in Bangkok, Thailand. Of the 2,546 individuals enrolled in the trial based on high risk for infection through injection drug use (IDU), we obtained clinical samples and HIV-1 sequence data (envelope glycoprotein gene gp120) from 215 individuals who became infected during the trial. Here, we used these data in combination with other publicly available gp120 sequences to perform a molecular surveillance and phylodynamic analysis of HIV-1 in Thailand.Phylogenetic and population genetic estimators were used to assess HIV-1 gp120 diversity as a function of vaccination treatment, viral load (VL) and CD4(+) counts, to identify transmission clusters and to investigate the timescale and demographics of HIV-1 in Thailand. Three HIV-1 subtypes were identified: CRF01_AE (85% of the infections), subtype B (13%) and CRF15_AE (2%). The Bangkok IDU cohort showed more gp120 diversity than other Asian IDU cohorts and similar diversity to that observed in sexually infected individuals. Moreover, significant differences (P<0.02) in genetic diversity were observed in CRF01_AE IDU with different VL and CD4(+) counts. No phylogenetic structure was detected regarding any of the epidemiological and clinical factors tested, although high proportions (35% to 50%) of early infections fell into clusters, which suggests that transmission chains associated with acute infection play a key role on HIV-1 spread among IDU. CRF01_AE was estimated to have emerged in Thailand in 1984.5 (1983-1986), 3-6 years before the first recognition of symptomatic patients (1989). The relative genetic diversity of the HIV-1 population has remained high despite decreasing prevalence rates since the mid 1990s.Our study and recent epidemiological reports indicate that HIV-1 is still a major threat in Thailand and suggest that HIV awareness and prevention needs to be strengthened to avoid AIDS resurgence.

SUBMITTER: Perez-Losada M

PROVIDER: S-EPMC3053363 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature

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Phylodynamics of HIV-1 from a phase III AIDS vaccine trial in Bangkok, Thailand.

Pérez-Losada Marcos M Jobes David V DV Sinangil Faruk F Crandall Keith A KA Arenas Miguel M Posada David D Berman Phillip W PW

PloS one 20110310 3

<h4>Background</h4>In 2003, a phase III placebo-controlled trial (VAX003) was completed in Bangkok, Thailand. Of the 2,546 individuals enrolled in the trial based on high risk for infection through injection drug use (IDU), we obtained clinical samples and HIV-1 sequence data (envelope glycoprotein gene gp120) from 215 individuals who became infected during the trial. Here, we used these data in combination with other publicly available gp120 sequences to perform a molecular surveillance and phy ...[more]

PMID: 21423744

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Project description:BackgroundThailand has achieved global acclaim for its response to HIV/AIDS. However, the success of some of the country's most well-known initiatives was by no means a foregone conclusion. Policy entrepreneurs on the periphery of power had to achieve buy-in from stakeholders in state and society to scale and mainstream their ideas. This paper offers a comparative and historical understanding the process by which three of the country's most well-known initiatives came into being: a civil society campaign to promote condom usage; a Ministry of Public Health program that aimed to prevent the spread of Human Immunodeficiency Virus (HIV) by targeting high-risk populations (the 100% condom program); and a universal Prevention of Mother-To-Child Transmission (PMTCT) program.MethodsThe research relied on existing literature and interviews with high-ranking ministerial officials, representatives from international and non-governmental organizations, professors, and philanthropic organizations, in addition to a review of the existing literature. Taking a comparative and historical approach that is common within political science and sociology, we analysed the in-depth qualitative interviews in relation to the literatures and used an inductive cross-case analysis aimed to draw out critical features that the initiatives shared in common.ResultsCommon factors in HIV/AIDS prevention that cut across the three key cases include policy entrepreneurs who championed the programs, successful demonstration projects that produced a credible evidence base for policy adoption, and a diverse set of institutional partners that played critical roles in helping to mainstream their initiatives into national HIV/AIDS policy and scale programs nationally. The findings from this comparative research project have implications not only for the building of understanding related to one single project, but for broader theoretical understanding related to the mainstreaming of health policy from peripheral spaces of power.ConclusionsThis analysis draws out the role that demonstration projects played in building a credible evidence base for policy adoption and the role that a diverse set of institutional partners played in elevating the profile of policy entrepreneurs' ideas and helping to scale them nationally as state policy. Success was contingent on entrepreneurs first identifying and then taking advantage of different political opportunities that arose during each of the historical periods. Over time, these initiatives have evolved from vertical programs into an integrated program, in parallel with the evolution of the HIV/AIDS landscape at the global level.

Project description:BackgroundWith the persistent challenges towards controlling the HIV epidemic, there is an ongoing need for research into HIV vaccines and drugs. Sub-Saharan African countries--worst affected by the HIV pandemic--have participated in the conduct of clinical trials for HIV vaccines. In Kenya, the Kenya AIDS Vaccine Initiative (KAVI) at the University of Nairobi has conducted HIV vaccine clinical trials since 2001.MethodologyParticipants were recruited after an extensive informed consent process followed by screening to determine eligibility. Screening included an assessment of risk behavior, medical history and physical examination, and if clinically healthy, laboratory testing. In the absence of locally derived laboratory reference ranges, the ranges used in these trials were derived from populations in the West.Principal findingsTwo hundred eighty-one participants were screened between 2003 and 2006 for two clinical trials. Of these, 167 (59.4%) met the inclusion/exclusion criteria. Overall, laboratory abnormalities based on the non-indigenous laboratory references used were the most frequent reasons (61.4%) for ineligibility. Medical abnormalities contributed 30.7% of the total reasons for ineligibility. Based on the laboratory reference intervals now developed from East and Southern Africa, those ineligible due to laboratory abnormalities would have been 46.3%. Of the eligible participants, 18.6% declined enrollment.ConclusionsParticipant recruitment for HIV vaccine clinical trials is a rigorous and time-consuming exercise. Over 61% of the screening exclusions in clinically healthy people were due to laboratory abnormalities. It is essential that laboratory reference ranges generated from local populations for laboratory values be used in the conduct of clinical trials to avoid unnecessary exclusion of willing participants and to avoid over-reporting of adverse events for enrolled participants.Trial registrationProtocol IAVI VRC V001 [1]. ClinicalTrials.gov NCT00124007 Protocol IAVI 010 [2](registration with ClincalTrials.gov is in progress) Protocols IAVI 002 and IAVI 004 are Phase 1 trials only mentioned in introductory paragraphs; details will not be reported. Registration was not required when they were conducted.

Dataset Information

Phylodynamics of HIV-1 from a phase III AIDS vaccine trial in Bangkok, Thailand.

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Phylodynamics of HIV-1 from a phase III AIDS vaccine trial in Bangkok, Thailand.

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