Safety and Immunogenicity of Env 2-3, a Human Immunodeficiency Virus Type 1 Candidate Vaccine, in Combination with a Novel Adjuvant, MTP-PE/MF59

ABSTRACT We investigated the safety and immunogenicity of a candidate HIV-1 vaccine, Env 2-3 (Chiron Biocine Co.), in combination with an adjuvant emulsion, MF59, with or without an additional immune modulator, MTP-PE, in 78 healthy HIV-1-seronegative adults. Sixteen subjects participated in a dose escalation study of MTP-PE in MF59 without Env 2-3, given at 0 and 1 months; 48 subjects participated in a study of a fixed dose of 30 μg of Env 2-3 in MF59 with increasing doses of MTP-PE (0, 5, 10, 25, 50, and 100 μg), and 14 subjects participated in a study of 100 μg of Env 2-3 in MF59 without MTP-PE. Subjects were assigned to study groups under a randomized, double-blind allocation. Subjects received immunization at 0, 1, and 6 months, and had the option of receiving a fourth dose at 12–18 months. Env 2-3 in MTP-PE/MF59 was associated with significant reactogenicity, in that severe, although self-limited systemic and/or local reactions occurred in 15 of 30 vaccinees. In contrast, Env 2-3 in MF59 without MTP...