Long-term protection of chimpanzees against high-dose HIV-1 challenge induced by immunization

Nat Med. 1997 Jun;3(6):651-8. doi: 10.1038/nm0697-651.


A combination AIDS vaccine approach consisting of priming with adenovirus-HIV-1MN gp160 recombinants followed by boosting with HIV-1SF2 gp120 was evaluated in chimpanzees. Long-lasting protection, requiring only three immunizations, was achieved against a low-dose challenge with the SF2 strain of HIV-1 and a subsequent high-dose SF2 challenge administered 1 year later without an intervening boost. Notably, neutralizing antibody responses against both clinical and laboratory isolates developed in three chimpanzees and persisted until the time of high-dose challenge. The possibility that cytotoxic T-lymphocytes contribute to low-dose protection of a chimpanzee lacking neutralizing antibodies is suggested. Our results validate the live vector priming/subunit booster approach and should stimulate interest in assessing this combination vaccine approach in humans.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoviridae / immunology*
  • Animals
  • Female
  • HIV Envelope Protein gp120 / immunology*
  • HIV Envelope Protein gp160 / immunology*
  • HIV Infections / immunology
  • HIV Infections / prevention & control
  • HIV-1 / pathogenicity*
  • Pan troglodytes
  • Recombinant Fusion Proteins / administration & dosage
  • Recombinant Fusion Proteins / immunology*
  • T-Lymphocytes, Cytotoxic / physiology
  • Vaccination / methods*
  • Vaccines / administration & dosage


  • HIV Envelope Protein gp120
  • HIV Envelope Protein gp160
  • Recombinant Fusion Proteins
  • Vaccines