title: Placebo-controlled phase 3 trial of a recombinant glycoprotein 120 vaccine to prevent HIV-1 infection.
abstract: BACKGROUND
  A vaccine is needed to prevent human immunodeficiency virus type 1 (HIV-1) infection.
  
  
  METHODS
  A double-blind, randomized trial of a recombinant HIV-1 envelope glycoprotein subunit (rgp120) vaccine was conducted among men who have sex with men and among women at high risk for heterosexual transmission of HIV-1. Volunteers received 7 injections of either vaccine or placebo (ratio, 2 : 1) over 30 months. The primary end point was HIV-1 seroconversion over 36 months.
  
  
  RESULTS
  A total of 5403 volunteers (5095 men and 308 women) were evaluated. The vaccine did not prevent HIV-1 acquisition: infection rates were 6.7% in 3598 vaccinees and 7.0% in 1805 placebo recipients; vaccine efficacy (VE) was estimated as 6% (95% confidence interval, -17% to 24%). There were no significant differences in viral loads, rates of antiretroviral-therapy initiation, or the genetic characteristics of the infecting HIV-1 strains between treatment arms. Exploratory subgroup analyses showed nonsignificant trends toward efficacy in preventing infection in the highest risk (VE, 43%; n=247) and nonwhite (VE, 47%; n=914) volunteers (P=.10, adjusted for multiple subgroup comparisons).
  
  
  CONCLUSIONS
  There was no overall protective effect. The efficacy trends in subgroups may provide clues for the development of effective immunization approaches.
authors.affiliation: University of California at Davis Medical Center, USA.
authors.forename: Neil M
authors.initials: NM
authors.lastname: Flynn
authors.forename: Donald N
authors.initials: DN
authors.lastname: Forthal
authors.forename: Clayton D
authors.initials: CD
authors.lastname: Harro
authors.forename: Franklyn N
authors.initials: FN
authors.lastname: Judson
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Mayer
authors.forename: Michael F
authors.initials: MF
authors.lastname: Para
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology; D000293:Adolescent; D000328:Adult; D018450:Disease Progression; D005260:Female; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015658:HIV Infections / Q000517:prevention & control*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012309:Risk-Taking; D013997:Time Factors; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D016915:AIDS Vaccines; D015699:HIV Envelope Protein gp120; D014614:Vaccines, Synthetic