High-Dose Recombinant Canarypox Vaccine Expressing HIV-1 Protein, in Seronegative Human Subjects

BackgroundIn clinical trials, canarypox ALVAC–human immunodeficiency virus (HIV) vaccines have been shown to elicit human HIV–specific cytotoxic T lymphocyte (CTL) responses in some but not all healthy uninfected adults MethodsA clinical trial was conducted to examine whether the vaccine vCP1452 would elicit a greater HIV-specific CTL response when given at a dose of 108.0 TCID50 (60 participants) than when given at the regular dose, 107.26 TCID50 (40 participants); as a control, a placebo vaccine preparation also was administered (10 participants) ResultsTwo weeks after the last vaccination in a series, HIV-specific CTL responses were not significantly different when measured by either chromium-release assay (8% and 16% in the high- and regular-dose recipients, respectively) or interferon-γ ELISpot assay (8% and 15% in the high- and regular-dose recipients, respectively); moreover, recipients of the higher dose had greater local and systemic reactions (P