Strong and persistent CD4+ T-cell response in healthy adults immunized with a candidate HIV-1 vaccine containing gp120, Nef and Tat antigens formulated in three Adjuvant Systems

This randomized double-blind study aimed to determine the safety and immunogenicity of a gp120/NefTat candidate human immunodeficiency virus type 1 (HIV-1) vaccine formulated with one of three different Adjuvant Systems (AS02A, AS02V and AS01B) in healthy HIV-seronegative adults. All vaccine formulations induced strong HIV-specific CD4+ T-cell responses characterized by high lymphoproliferative capacity and IL-2 production that were still detectable 18 months after last immunization, with strongest responses seen in the AS01B group. Broad coverage was demonstrated against gp120, and to a lesser extent Nef, derived from the most common circulating clades (B, C and circulating recombinant form [CRF]-01). All vaccine formulations exhibited acceptable safety and reactogenicity profiles. The demonstration of superior CD4+ T-cell induction by AS01B provides important guidance for future HIV vaccine development.