7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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Experience with seventeen HIV vaccine efficacy trials in chimpanzees.

Int Conf AIDS 1991 Jun 16-21; 7:88 (abstract no. F.A.2)
Eichberg JW; Southwest Foundation for Biomedical Research, San Antonio, TX, USA

OBJECTIVE: To evaluate the efficacy of various HIV vaccines to prevent infection in chimpanzees.

METHODS: The following HIV vaccines were used to actively or passively immunize a total of 55 chimpanzees: 1. synthetic peptide (735-752); 2. vaccinia-env; 3. rgp120 (CHO, approximately 50% pure, approximately 50% clipped at V3 loop); 4. HIVIG (high dose challenge); 5. recombinant peptide (350-674); 6. vaccinia-gag; 7. vaccinia-gp120 (truncated); 8. vaccinia-env and gp120 (t) 9. idiotypic antibodies (anti-CD4 cocktail); 10. env 2-3 (yeast); 11. p55; 12. PBl (295-474); 13. whole inactivated HIV; 14. adenovirus-gag and/or env recombinants; 15. rgp160 (CHO, approximately 95% pure, approximately 40% clipped, no TMP); 16. rgp120 (CHO, greater than 99% pure, not clipped); and 17. HIVIG (low dose challenge).

RESULTS: Cellular immunity was induced by most vaccines (except trials 1, 5, 9) but was not able to confer protection from infections when animals were challenged (trials 2, 3). While humoral immunity (ELISA and/or Western blot) was induced with virtually all vaccines, only passive immunization with HIVIG (trials 4, 17) and active vaccination with rgp160 and rgp120 (trials 15, 16) resulted in high titers of neutralizing antibodies. Protection from HIV infection was achieved only with rgp120 (trial 16) and HIVIG (trial 17). All other vaccines either did not confer protection from infection or did not warrant a challenge with live HIV.

CONCLUSION: Based on the successful protection results with rgp120 (trial 16) and HIVIG (trial 17) and the failure of all other vaccines it is evident that neutralizing antibodies and high anti-V3 loop reactivity combined with a low dose challenge are prerequisite for the development of efficacious HIV vaccines.

Keywords: AEGIS, AIDS Vaccines, Pan troglodytes, HIV Antibodies, HIV Envelope Protein gp120, HIV Infections, HIV, HIV Antigens, Vaccination, Immunity, Cellular, Antibody Formation, Reverse Transcriptase Inhibitors, Immunization, Passive, Vaccinia, VaxSyn HIV-1 (gp160) vaccine, Animal, immunology, ICA7
910616
FA2

Copyright © 1991 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.