BOOSTER IMMUNIZATION OF HIV-1 NEGATIVE VOLUNTEERS WITH HGP-30 VACCINEINDUCES PROTECTION AGAINST HIV-1 VIRUS CHALLENGE IN SCID MICE

Eleven HIV-1 seronegative subjects previously injected with an HIV-1 p 17 synthetic peptide vaccine (HGP-30) were given two booster immunizat ions to evaluate memory cell responses and the ability to boost cellul ar and humoral immune responses. Five of 11 subjects showed a signific ant increase in their antibody titres to HGP-30 or p17 and 6/11 had T- cell proliferation responses to either HGP-30 or p17. HIV-1 virus chal lenge studies in SCID mice demonstrated that 39 of 50 mice (78%) recei ving PBMC from 5 of the HGP-30 immunized subjects were protected from infection with a different strain of HIV-1 compared to 4 of 30 mice (1 3%) that received PBMC from 3 non-immunized subjects (p < 0.001). Thes e studies show that booster immunizations with HGP-30 vaccine are safe and non-toxic and induce protective cell mediated immune responses. ( C) 1998 Elsevier Science Ltd. All rights reserved.