Placebo-controlled phase 3 trial of a recombinant glycoprotein 120 vaccine to prevent HIV-1 infection

J Infect Dis. 2005 Mar 1;191(5):654-65. doi: 10.1086/428404. Epub 2005 Jan 27.


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.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase III
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • AIDS Vaccines* / immunology
  • Adolescent
  • Adult
  • Disease Progression
  • Female
  • HIV Envelope Protein gp120 / immunology*
  • HIV Infections / prevention & control*
  • HIV-1 / immunology*
  • Humans
  • Male
  • Middle Aged
  • Risk Factors
  • Risk-Taking
  • Time Factors
  • Vaccines, Synthetic / immunology


  • AIDS Vaccines
  • HIV Envelope Protein gp120
  • Vaccines, Synthetic