Demographic Factors That Influence the Neutralizing Antibody Response in Recipients of Recombinant HIV-1 gpl20 Vaccines

We compared neutralizing antibody responses in human immunodeficiency virus (HIV) type 1 gpl20 vaccine recipients by age, sex, and race. Four phase 1 or 2 trials involving 505 vaccinated subjects were analyzed. Age and sex had no detectable effect on neutralizing antibody responses. However, race influenced the response to one vaccine, MN gpl20, in alum. Four inoculations with this vaccine generated higher serum titers of neutralizing antibodies in African Americans than in whites. Despite potent neutralization of T cell lineadapted HIV-1, serum from these African Americans failed to neutralize primary HIV-1 isolates. Neutralizing antibody responses did not differ between races when SF2 gpl20 in MF-59 was administered either alone or with recombinant canarypox vCP205; they also did not differ when vCP1452 was administered either alone or with AIDSVAX B/B in alum. These data indicate that race may affect the neutralizing antibody response to some gpl20 immunogens. To fully evaluate immunogenicity, clinical trials of candidate vaccines should enroll diverse populations of subjects.