6th International AIDS Conference San Francisco, California, USA — June 20-23, 1990

Int Conf AIDS 1990 Jun 20-23; 6:326 (abstract no. 1049)
Ellerbeck E, Viscidi R, Midthun K, Clements ML, Smith G; Johns Hopkins University, Baltimore, Maryland USA

OBJECTIVE: To characterize the gp160 antibody response of healthy adults participating in a multi-centered phase I safety and immunogenicity trial of baculovirus-expressed gp160 (rgp160) of HIV-1 (VaxSyn HIV-1, MicroGeneSys, Inc.).

METHODS: HIV-seronegative volunteers were vaccinated at 0, 1, 6, and 18 months with 40 or 80 ug rgp160 (N=23), hepatitis B vaccine (N=11) or placebo (N=16). Serial serum specimens from these volunteers were tested for IgG antibody by a noncompetitive solid phase enzyme immunoassay (EIA) using rgp160 as antigen.

RESULTS: Twenty of 23 (87%) rgp160 vaccinees had a significant rise in IgG gp160 antibody titer after the third dose of vaccine; positive titers ranged from 1:200 to 1:6400. By 18 months after the initial vaccination, only 8 rgp160 vaccinees still had detectable gp160 antibody. After a fourth dose of rgp160, gp160 antibody was detected in 22 rgp160 vaccinees; their EIA gp160 antibody titers ranged from 1:200 to 1:25,600. Peak gp160 antibody responses of 80 ug vaccinees were higher than those receiving 40 ug of rgp 160.

CONCLUSION: These findings indicated that immunization with baculovirus-expressed rgp160 primed the humoral immune systems of adults and that revaccination could augment the antibody response 12 months after the last dose.

900620
1049

Copyright © 1990 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.