A Phase I Multicenter Clinical Trial to Evaluate the Safety and Immunogenicity of Immuno-AG Recombinant HIV gp160 in Asymptomatic HIV Seropositive Individuals

To determine the safety and immunogenicity of vaccinia-derived HIV-1 recombinant envelope glycoprotein (gp160) in asymptomatic HIV-infected adult volunteers. To compare safety and immunogenicity of two different schedules of gp160 administration. To examine the effects of gp160 and hepatitis B vaccine (Engerix-B) on various markers of viral load and on selected immune parameters. Potentiation of a patient's immune response to HIV might possibly prolong the period of clinical latency and protect the patient indefinitely. Preliminary results from a study of Immuno-AG recombinant gp160 vaccine in healthy volunteers not infected with HIV suggest that the vaccine is safe and produces antibodies against the virus. Because another previous study failed to demonstrate a specific anti-HIV response in patients injected with a recombinant vaccinia virus containing HIV-1 genes, this study is also testing the immunotherapeutic role of other immunizations (such as hepatitis B vaccination) that would be expected to induce a nonspecific immune response in HIV-infected persons. Potentiation of a patient's immune response to HIV might possibly prolong the period of clinical latency and protect the patient indefinitely. Preliminary results from a study of Immuno-AG recombinant gp160 vaccine in healthy volunteers not infected with HIV suggest that the vaccine is safe and produces antibodies against the virus. Because another previous study failed to demonstrate a specific anti-HIV response in patients injected with a recombinant vaccinia virus containing HIV-1 genes, this study is also testing the immunotherapeutic role of other immunizations (such as hepatitis B vaccination) that would be expected to induce a nonspecific immune response in HIV-infected persons. Fifty-five healthy HIV-positive volunteers are randomly assigned to one of the following treatment arms: six injections (arm I) or four injections (arm II) of HIV-1 gp160 vaccine, four injections of hepatitis B vaccine as a non-HIV viral vaccine control (arm III), or six placebo injections consisting of the adjuvant vehicle used for the gp160 vaccine (arm IV). Immunizations or placebo are given at 4-week intervals for 5 months. To maintain blinding, adjuvant vehicle placebo is administered on days 84 and 112 to those volunteers receiving four instead of six vaccine injections (arms II and III). Volunteers are followed at 4-month intervals for 2 years.