title: Lack of increased HIV risk behavior among injection drug users participating in the AIDSVAX B/E HIV vaccine trial in Bangkok, Thailand.
abstract: OBJECTIVE
  To determine whether HIV vaccine trial participation leads to increased risk behavior through beliefs about vaccine protection against infection.
  
  
  METHODS
  Changes in risk behavior were evaluated among 2545 injection drug users participating in the AIDSVAX B/E vaccine trial in Bangkok, enrolled from March 1999 to August 2000. Demographic characteristics, beliefs and risk behavior were assessed at baseline and every 6 months thereafter. Risk-reduction counseling was provided at every study visit. Generalized estimation-equation logistic regression analysis was used to study trends in risk behavior and associated factors.
  
  
  RESULTS
  Participants were 93.4% male, their median age was 26 years, and 67.2% had at least secondary education. At baseline, 61.3% were receiving methadone detoxification and 20.9% were receiving methadone maintenance. From baseline to the 12-month follow-up visit, injection drug use decreased from 93.8% to 66.5% (P < 0.001) and needle sharing from 33.0% to 17.5% (P < 0.001). Multivariate analyses showed earlier follow-up time (at baseline and 6 months) and believing the vaccine to be efficacious associated with more-frequent injecting; younger age and lower education associated with less-frequent injecting. Earlier follow-up time (at baseline), younger age, and injection of methamphetamine and midazolam were associated with more-frequent needle sharing; methadone treatment and injecting less than weekly were associated with less-frequent needle sharing.
  
  
  CONCLUSIONS
  Injection drug use and needle sharing decreased during the first 12 months of the trial. No increases in risk behavior in relation to beliefs about vaccine protection against HIV infection could be identified.
authors.affiliation: Thailand Ministry of Public Health-US Centers for Disease Control and Prevention Collaboration, Nonthaburi.
authors.forename: Frits
authors.initials: F
authors.lastname: van Griensvan
authors.forename: Jaranit
authors.initials: J
authors.lastname: Keawkungwal
authors.forename: Jordan W
authors.initials: JW
authors.lastname: Tappero
authors.forename: Udomsak
authors.initials: U
authors.lastname: Sangkum
authors.forename: Punnee
authors.initials: P
authors.lastname: Pitisuttithum
authors.forename: Suphak
authors.initials: S
authors.lastname: Vanichseni
authors.forename: Pravan
authors.initials: P
authors.lastname: Suntharasamai
authors.forename: Karin
authors.initials: K
authors.lastname: Orelind
authors.forename: Carolyn
authors.initials: C
authors.lastname: Gee
authors.forename: Kachit
authors.initials: K
authors.lastname: Choopanya
mesh_terms: D016915:AIDS Vaccines; D000328:Adult; D000368:Aged; D001294:Attitude to Health; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016485:Needle Sharing; D010353:Patient Education as Topic; D012309:Risk-Taking; D012725:Sexual Behavior; D012747:Sexual Partners; D015819:Substance Abuse, Intravenous / Q000453:epidemiology / Q000523:psychology*; D013785:Thailand / Q000453:epidemiology
chemical_list: D016915:AIDS Vaccines; C112734:AIDSVAX