title: HIV Epidemic in Asia: Implications for HIV Vaccine and Other Prevention Trials.
abstract: An overall decrease of HIV prevalence is now observed in several key Asian countries due to effective prevention programs. The decrease in HIV prevalence and incidence may further improve with the scale-up of combination prevention interventions. The implementation of future prevention trials then faces important challenges. The opportunity to identify heterosexual populations at high risk such as female sex workers may rapidly wane. With unabating HIV epidemics among men who have sex with men (MSM) and transgender (TG) populations, an effective vaccine would likely be the only option to turn the epidemic. It is more likely that efficacy trials will occur among MSM and TG because their higher HIV incidence permits smaller and less costly trials. The constantly evolving patterns of HIV-1 diversity in the region suggest close monitoring of the molecular HIV epidemic in potential target populations for HIV vaccine efficacy trials. CRF01_AE remains predominant in southeast Asian countries and MSM populations in China. This relatively steady pattern is conducive to regional efficacy trials, and as efficacy warrants, to regional licensure. While vaccines inducing nonneutralizing antibodies have promise against HIV acquisition, vaccines designed to induce broadly neutralizing antibodies and cell-mediated immune responses of greater breadth and depth in the mucosal compartments should be considered for testing in MSM and TG. The rationale and design of efficacy trials of combination prevention modalities such as HIV vaccine and preexposure prophylaxis (PrEP) remain hypothetical, require high adherence to PrEP, are more costly, and present new regulatory challenges. The prioritization of prevention interventions should be driven by the HIV epidemic and decided by the country-specific health and regulatory authorities. Modeling the impact and cost-benefit may help this decision process.
authors.affiliation: 1 SEARCH, The Thai Red Cross AIDS Research Centre , Bangkok, Thailand .
authors.forename: Nittaya
authors.initials: N
authors.lastname: Phanuphak
authors.affiliation: 2 HIV, Hepatitis, and STI Unit, WHO Regional Office for the Western Pacific , Manila, Philippines .
authors.forename: Ying-Ru
authors.initials: YR
authors.lastname: Lo
authors.affiliation: 3 National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention , Beijing, China .
authors.forename: Yiming
authors.initials: Y
authors.lastname: Shao
authors.affiliation: 4 Johns Hopkins University School of Medicine , Baltimore, Maryland.|5 Y.R. Gaitonde Centre for AIDS Research and Education (YRG CARE) , Chennai, India .
authors.forename: Sunil Suhas
authors.initials: SS
authors.lastname: Solomon
authors.affiliation: 6 Department of Retrovirology, U.S. Army Medical Component, Armed Forces Institute of Medical Sciences (AFRIMS) , Bangkok, Thailand .
authors.forename: Robert J
authors.initials: RJ
authors.lastname: O'Connell
authors.affiliation: 7 U.S. Military HIV Research Program, Walter Reed Army Institute of Research , Silver Spring, Maryland.
authors.forename: Sodsai
authors.initials: S
authors.lastname: Tovanabutra
authors.affiliation: 7 U.S. Military HIV Research Program, Walter Reed Army Institute of Research , Silver Spring, Maryland.
authors.forename: David
authors.initials: D
authors.lastname: Chang
authors.affiliation: 7 U.S. Military HIV Research Program, Walter Reed Army Institute of Research , Silver Spring, Maryland.
authors.forename: Jerome H
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 8 U.S. Military HIV Research Program , Bethesda, Maryland.|9 The Henry M. Jackson Foundation for the Advancement of Military Medicine , Bethesda, Maryland.
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Excler
mesh_terms: D016915:AIDS Vaccines / Q000008:administration & dosage* / Q000276:immunology* / Q000302:isolation & purification; D001208:Asia / Q000453:epidemiology; D002986:Clinical Trials as Topic; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D058872:Epidemics; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control*; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D063106:Transgender Persons; D005260:Female
chemical_list: D016915:AIDS Vaccines