A phase I/II trial of HIVSF2 gp120/MF59 vaccine in seronegative Thais

Fifty-two human immunodeficiency virus type 1, seronegative Thai adults fro m the community were enrolled in a double-blind, placebo controlled, phase I/II trial of HIV SF2 gp120/MF59 vaccine to determine the safety and immuno genicity of this recombinant, B clade, HIV envelope protein vaccine. Twenty -six subjects were enrolled at each of two sites in Thailand, Bangkok and C hiang Mai, Twelve subjects received placebo and 40 subjects received vaccin e (50 mu g). Subjects were immunized according to one of two schedules, 0, 1 and 4 or 0, 1 and 6 months. The frequency of adverse reactions was not di fferent between placebo and vaccine subjects, nor between immunization sche dules. Of vaccinees, all developed high-titer binding antibody to the immun ogen (rgp120), 39 developed neutralizing antibody (NA) responses against ho mologous virus (HIV-1(SF2)), and 22 developed NA against heterologous virus (HIV-1(MN)). No subject demonstrated intercurrent HIV infection, however s creening EIA reactivity occurred in 27% of recipients. Thus, this candidate HIV vaccine was found to be safe and immunogenic in Thai adults, laying th e foundation for development of a subtype E construct in this population. ( C) 2000 Elsevier Science Ltd. All rights reserved.