title: Sexual risk behaviour of Canadian participants in the first efficacy trial of a preventive HIV-1 vaccine.
abstract: BACKGROUND
  Phase I and phase II HIV-1 vaccine trials have revealed increases in risky sexual activity among study subjects during the trials, perhaps because the subjects believe that the vaccine being tested is efficacious; subjects may thus suffer harm from their participation. We evaluated the sexual behaviour of Canadian men who have sex with men (MSM) who participated in the phase III Vax004 trial of an HIV-1 vaccine.
  
  
  METHODS
  Using self-reports of sexual behaviours during the 6 months before trial entry as a baseline, we determined changes in reported sexual behaviour after 6, 12 and 18 months of participation in the trial.
  
  
  RESULTS
  Of 291 HIV-seronegative MSM enrolled from July to October 1999, 260 (89%) completed 18 months of follow-up, 19 (7%) experienced seroconversion, and 12 (4%) did not complete follow-up. Unprotected receptive anal intercourse during the previous 6 months with partners whose HIV-1 serostatus was positive or unknown was reported by 21% of men at enrollment and by 27% at any point during 18 months of follow-up. No increase in this behaviour from baseline was reported by participants, including among men who were motivated to enroll because of expected protection from HIV-1 infection, men who believed they had received the vaccine, men who believed that the vaccine had greater than 50% efficacy, or men who believed that they had received the vaccine and that vaccine efficacy was greater than 50%.
  
  
  CONCLUSIONS
  MSM can be successfully enrolled in HIV-1 vaccine efficacy trials without evident increases in those sexual behaviours most associated with HIV-1 risk.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC. tlampinen@cfenet.ubc.ca
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lampinen
authors.forename: Keith
authors.initials: K
authors.lastname: Chan
authors.forename: Robert S
authors.initials: RS
authors.lastname: Remis
authors.forename: Maraki Fikre
authors.initials: MF
authors.lastname: Merid
authors.forename: Melanie
authors.initials: M
authors.lastname: Rusch
authors.forename: Jean
authors.initials: J
authors.lastname: Vincelette
authors.forename: Ken
authors.initials: K
authors.lastname: Logue
authors.forename: Vladimir
authors.initials: V
authors.lastname: Popovic
authors.forename: Michel
authors.initials: M
authors.lastname: Alary
authors.forename: Martin T
authors.initials: MT
authors.lastname: Schechter
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hogg
mesh_terms: D016915:AIDS Vaccines; D000328:Adult; D005500:Follow-Up Studies; D015658:HIV Infections / Q000517:prevention & control* / Q000523:psychology; D006679:HIV Seropositivity; D015497:HIV-1; D018451:Homosexuality, Male; D006801:Humans; D013287:Illicit Drugs; D008297:Male; D012725:Sexual Behavior / Q000706:statistics & numerical data; D047568:Unsafe Sex / Q000706:statistics & numerical data*
chemical_list: D016915:AIDS Vaccines; D013287:Illicit Drugs