Sricharoen MigasenaPravan SuntharasamaiPunnee PitisuttithumDwip KitayapornChantapong WasiWei HuangSuphak VanichseniCharnchai KoompongJaranit KaewkungwalSuwanee RakthamTina IppolitoCarl HansonTimothy GregoryWilliam L. HeywardPhillip BermanDonald P. FrancisMahidol UniversityGenentech IncorporatedBangkok Metropolitan AdministrationVaxGen, Inc.California Department of Health ServicesOrganisation Mondiale de la SanteCenters for Disease Control and Prevention2018-09-072018-09-072000-05-01AIDS Research and Human Retroviruses. Vol.16, No.7 (2000), 655-663088922292-s2.0-0034178248https://repository.li.mahidol.ac.th/handle/123456789/25986A randomized, double-blind, placebo-controlled phase I/II study of AIDSVAX® (MN) was conducted among injecting drug users in Bangkok, Thailand. Four doses of vaccine (300 μg of MN-rgp120 in alum) or placebo (alum) were given at study entry and at 1, 6, and 12 months. The objectives of the study were to evaluate (1) the feasibility of conducting vaccine trials in this population; (2) the safety of this candidate AIDS vaccine; and (3) the immunogenicity of this vaccine. Thirty-three volunteers (22 vaccine and 11 placebo recipients) were recruited. None were lost to follow-up during the 18-month study. Mild reactogenicity was noted, which was similar in both vaccine and placebo recipients. The vaccine induced anti-HIV-1 antibody in all vaccine recipients. Maximal titers of binding antibodies of MN-rgp120 and the V3 domain of MN-rgp120 were induced after the third (6 month) dose while maximal neutralizing antibodies followed the fourth (12 month) dose. The vaccine-induced antibodies from several volunteers were capable of neutralizing macrophage-tropic, subtype B viruses (301660 and JRCSF) detected in a PBMC-based assay. Binding and neutralizing antibodies declined about 10- fold in the 6 months after the last boost. Two vaccinees became infected during the trial, both with subtype E viruses. A phase III efficacy trial, using a bivalent gp120, vaccine containing antigens from a subtype B virus (MN) and a subtype E virus (A244), was initiated in March 1999 in injecting drug users in Bangkok.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1089/088922200308882