Immune Responses to a Recombinant Human Immunodeficiency Virus Type 1 (HIV-1) gp160 Vaccine Among Adults with Advanced HIV Infection

Abstract

OBJECTIVE: To assess immunogenicity of recombinant human immunodeficiency virus type 1 (HIV-1) envelope vaccine (rgp160) in late HIV infection. STUDY DESIGN/METHODS: HIV-infected volunteers (n = 142), with CD4+ T lymphocyte counts of or =4-fold increase) against one or more gpl60 epitopes (C1, V3, C41, 448C). Delayed-type hypersensitivity (DTH) to intradermal gpl60, initially not present in any participant, developed after immunization in 41%, with higher prevalence in participants receiving the lower dose of vaccine. Both antibody and skin test responses occurred in 20-25% of vaccine recipients. Virtually all antibody and skin test responses occurred in participants with initial CD4+ cell counts of >100 cells/mm3. IFN-gamma had no significant effect on immune response. Immunization was well tolerated. Trends in CD4+ cell count, clinical events, and laboratory findings correlated with baseline CD4+ T lymphocyte count stratum and not with immunization regimen. Opportunistic conditions occurred at expected rates. Viral load trends (p24 antigen in all participants and viral RNA by reverse transcription-polymerase chain reaction in a subset of 26 participants) did not correlate with immunization regimen. CONCLUSION: Immunization of patients with advanced HIV infection with rgpl60 resulted in new and augmented humoral and DTH responses, without unexpected significant adverse events or evident clinical benefits attributable to immunization.