Publications by authors named "Chirasak Khamboonruang"

The RV144 HIV-1 vaccine trial (Thailand, 2003 to 2009), using immunogens genetically matched to the regional epidemic, demonstrated the first evidence of efficacy for an HIV-1 vaccine. Here we studied the molecular evolution of the HIV-1 epidemic from the time of immunogen selection to the execution of the efficacy trial. We studied HIV-1 genetic diversity among 390 volunteers who were deferred from enrollment in RV144 due to preexisting HIV-1 infection using a multiregion hybridization assay, full-genome sequencing, and phylogenetic analyses.

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To assess qualities and outcomes of women participating in a large, community-based HIV vaccine trial, the present study was conducted among female participants of the RV 144 prime-boost trial in Thailand from 2003 to 2009. Qualities of participation refer to complete vaccination, retention, and status change. Outcomes of participation refer to incident rate, adverse event, and participation impact event.

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Background: The Thai phase 3 HIV vaccine trial RV 144 showed modest efficacy of a vaccine against HIV acquisition. Baseline variables of age, sex, marital status, and risk did not modify vaccine efficacy. We did a post-hoc analysis of the trial's data to investigate behavioural risk and efficacy every 6 months after vaccination.

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Background: The development of a safe and effective vaccine against the human immunodeficiency virus type 1 (HIV-1) is critical to pandemic control.

Methods: In a community-based, randomized, multicenter, double-blind, placebo-controlled efficacy trial, we evaluated four priming injections of a recombinant canarypox vector vaccine (ALVAC-HIV [vCP1521]) plus two booster injections of a recombinant glycoprotein 120 subunit vaccine (AIDSVAX B/E). The vaccine and placebo injections were administered to 16,402 healthy men and women between the ages of 18 and 30 years in Rayong and Chon Buri provinces in Thailand.

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Background: The development of an effective HIV-1 vaccine is critical to control the pandemic. A prime-boost HIV-1 vaccine trial assessing safety and immunogenicity was conducted in Thailand as part of an evaluation of candidate regimens for a phase 3 efficacy trial.

Methods: ALVAC-HIV (vCP1521), expressing circulating recombinant form 01_AE (CRF01_AE) gp120/subtype B LAI and subtype B Gag/Protease boosted with recombinant envelope oligomeric CRF01_AE gp160 (ogp160) or bivalent CRF01_AE/subtype B gp120 CM235/SF2, was evaluated in a phase 1/II trial of 130 HIV-negative Thai adults.

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Behavioral and social issues were investigated in 363 phase I/II preventive HIV-1 vaccine trial volunteers in Thailand. These issues included risk behavior, HIV knowledge, distress, and social consequences of vaccine trial participation. Data were collected at baseline and at 4-, 8-, and 12-month follow-up visits.

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This study investigates the self-reported history of HIV voluntary counseling and testing (VCT) among adults, aged 19-35 years, in northern Thailand. Participants were interviewed about their HIV testing history and risk behavior. Overall, 47% of 2251 participants had previously been tested, of whom 64% were tested at government clinics.

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The natural history and progression of HIV-1 infection in Thailand and other developing countries in Asia and Africa have not been well defined. Nevertheless, valid data are needed to evaluate the effects of interventions, which are designed to delay progression. We evaluated the progression to AIDS and death in 235 men who seroconverted during their 2 years of service in the Royal Thai Army.

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Safety and immunogenicity of 2 recombinant human immunodeficiency virus (HIV) type 1 envelope glycoprotein (gp) 120 vaccines derived from SF2 (subtype B) and CM235 (CRF01_AE, Thai E) were evaluated in 370 Thai adults at low risk of HIV infection. Various doses of CM235 (25, 50, or 100 microg) and SF2 (0, 25, or 50 microg) gp120 were used. Eighty volunteers received placebo.

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Factors believed to be predictive of retention through the recruitment and screening processes for preventive HIV trials were investigated in a large multisite phase I/II HIV vaccine trial in Thailand. Retention through recruitment was equal to or greater than in previous smaller trials with similar populations. The data suggested that recruitment proceeded in a stepwise manner with different influences at each step.

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Voluntary HIV counseling and testing (VCT) is a central component of comprehensive HIV prevention strategies targeting individual risk reduction. VCT data are essential for planning and improving HIV/AIDS intervention strategies. The objective of this study is to describe demographic profiles, reasons for seeking HIV counseling and testing, rate of declining HIV testing after pretest counseling, rate of failure to return for HIV test results, and HIV prevalence and associations among 3570 clients who sought VCT at Sansai Hospital in northern Thailand from 1995 to 1999.

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Epidemic HIV-1 infections were first recognized in Thailand in 1988 but increased dramatically in the 1990s primarily as a result of sexual transmission. The Ministry of Public Health instituted programs, including condom promotion during commercial sex, and health education to prevent HIV transmission. We assessed the HIV infection prevalence and risk behaviors among eight cohorts of 21-year-old randomly selected male military conscripts in northern Thailand between 1991 and 1998 to evaluate temporal trends in HIV infection and risk behavior.

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