Proliferative responses to HIV antigens are either absent or of small magnitude in HIV-infected patients, even in the early stages of infection when vigorous proliferative responses to recall antigens are still seen. Remune consists of an inactivated, gp120-depleted virus intended to stimulate HIV-specific immune responses. Remune has been reported to increase lymphocyte proliferative responses to HIV antigens in patients with high CD4 cell counts. Many other T-cell-dependent responses are also impaired in HIV-infected patients, such as after vaccination with hepatitis A or B vaccine. In this study, patients with moderately advanced HIV disease who have already received 52 weeks of either HAART or HAART plus IL-2 are vaccinated with Remune and a control recall immunogen, tetanus toxoid (TT), to evaluate whether these patients can develop new CD4 T-cell and CD8 T-cell responses to HIV-related antigens. The antibody response to hepatitis A and hepatitis B vaccinations also will be explored.

Fifty patients are enrolled in this substudy; 17 from the HAART only arm (Arm I of ACTG 328) and 33 from the HAART plus either CIV or subcutaneous IL-2 arms (Arms II and III of ACTG 328). All patients are vaccinated 3 times with Remune and twice with TT. If patients are hepatitis A total antibody negative, they receive hepatitis A vaccine twice. Additionally, if patients are hepatitis B surface antigen negative, hepatitis B core antibody and surface antibody negative, they receive hepatitis B vaccine 3 times. Patients who are negative for all hepatitis markers receive hepatitis A and B vaccines.

Week 0 of A5046s begins at or after Week 64 of ACTG 328 (for patients in the HAART-only arm) or 4 weeks after the initiation of the seventh or any subsequent IL-2 cycle of ACTG 328 (for patients in any of the IL-2-containing arms). [AS PER AMENDMENT 9/16/99: Patients can be screened through Week 124 of ACTG 328.] Patients receive Remune at Weeks 0, 8, and 16 and TT at Weeks 0 and 8. Hepatitis A and/or B vaccines are also given at these times, if indicated. Blood and skin tests are performed at Weeks 0, 8, 16, and 24 to measure immune response and lymphocyte proliferative responses.