Antibody to human immunodeficiency virus type 1 (HIV-1) gp160 in mucosal specimens of asymptomatic HIV-1-infected volunteers parenterally immunized with an experimental recombinant HIV-1 IIIB gp160 vaccine

Twenty-two human immunodeficiency virus type 1 (HIV-1)-infected, asymptomatic volunteers with CD4 cell counts of >600 cells/mm³ who were enrolled in a phase I immunotherapy trial comparing two schedules of immunization of an HIV-I IIIB-based recombinant gp160 (rgp160) experimental vaccine were evaluated for rgp160-specific antibodies in parotid saliva, genital secretions, and serum. When the study was unblinded, it was determined thai five volunteers had received rgp160 on a month 0, 1, 2, 3, 4, and 5 immunization schedule, seven volunteers had received rgp160 on a month 0, 1, 2, and 5 schedule, five had received alum/deoxycholate placebo, and seven had received a licensed hepatitis B virus vaccine. Five volunteers consented to the donation of parotid saliva but not genital secretions. Prior to immunization, parotid saliva specimens were available for 11 of 22 volunteers, seminal plasma (SP) specimens were available for 7 of 22 volunteers, cervicovaginal lavage (CVL) specimens were available for 5 of 22 volunteers, and serum was available for 22 of 22 volunteers. These baseline specimens and specimens collected at 1 and 7 months after the final immunizations were assessed by enzyme-linked immunosorbent assay for immunoglobulin G (IgG) and IgA antibodies specific for HIV-1 LA1 rgp160 or HIV-I MN rgp160. No augmentation in HIV rgp160-specific IgG or IgA antibody production in either parotid saliva or serum specimens of vaccinees compared to that in controls was observed after immunization. There were insufficient numbers of SP or CVL specimens available for statistical comparisons between vaccinees and controls. Overall, anti-LA1 rgp160 IgG antibodies were detected in the parotid saliva specimens of 20 of 22 volunteers, the seminal plasma specimens of 11 of 11 volunteers, and the CVL specimens of 6 of 6 volunteers and in 21 of 22 serum specimens. Fewer volunteers expressed anti-LA1 rgp160 IgA antibodies in mucosal or serum specimens: 11 of 22 parotid saliva specimens, 3 of 11 SP specimens, 3 of 5 CVL samples, and 12 of 22 sera.