Human immunodeficiency virus type 1 (HIV-1) gp120-specific antibodies in neonates receiving an HIV-1 recombinant gp120 vaccine

Infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers were immunized at birth and at ages 4, 12, and 20 weeks with low-, medium-, or high-dose recombinant gp120 vaccine with MF59 adjuvant (HIV-1_SF-2; n = 52) or with MF59 alone as a placebo (n = 9). An accelerated schedule (birth and ages 2, 8, and 20 weeks) was used for an additional 10 infants receiving the defined optimal dose and for 3 infants receiving placebo. At 24 weeks, anti-gp120 ELISA titers were greater for vaccine-immunized than for placebo-immunized infants on both schedules, and 87% of vaccinees had a vaccine-induced antibody response. At 12 weeks, antibody titers of infants on the accelerated vaccine schedule exceeded those of infants receiving placebo (4949 vs. 551; P = .01), and 63% of the vaccinees met the response criteria. Thus, an accelerated schedule of gp120 vaccinations generated an antibody response to HIV-1 envelope distinct from transplacental maternal antibody by age 12 weeks. These results provide support for further studies of vaccine strategies to prevent mother-to-infant HIV-1 transmission.