Immunization of HIV-infected adults with a three-dose series of inactivated Mycobacterium vaccae

Heat-killed Mycobacterium vaccae vaccine was administered in a 3-dose schedule to 12 HIV-infected adults with CD4 cell counts > or = 300/mm3. Local and systemic side effects were monitored. Delayed-type hypersensitivity to purified protein derivative and Mycobacterium avium sensitin was measured at baseline and after the final dose. Antibody to aralipoarabinomannin, man-lipoarabinomannin, and a short-term culture filtrate of Mycobacterium tuberculosis were also measured. Lymphocyte proliferation responses to M avium sensitin and M vaccae sonicate were determined. Vaccine site induration was maximal at 2 days (median, 6 mm) and no systemic side effects were noted. Purified protein derivative skin test conversions did not occur. Changes in CD4 counts and HIV viral load were not significant. Three (27%) of 11 subjects who completed the trial showed either M avium skin test (n = 1) or short-term culture filtrate antibody (n = 2) responses. A three-dose schedule of M vaccae vaccine is safe and well tolerated in adults with early HIV infection and produces detectable immunologic responses in a subset of these subjects.