Pre-clinical Data on Recent Advances with HIV VLP Vaccine Presented at AIDS Vaccine 07 ...(ax scientists reported lastweek how to g...),Health

In addition to increasing the level of envelope protein in VLPs, the composition of envelope was modified to make it broadly reactive against several HIV strains. Genetic variation is a hallmark of HIV-1 infection and a major obstacle to HIV vaccine development. Scientists contributing to the current study designed centralized (ancestral and consensus) HIV-1 envelope constructs to help induce cross-reactive immune responses. One of these consensus HIV-1 envelope genes was used to generate the HIV-1 VLPs reported in this study.

In today's presentation, Dr. Liu described that in preclinical studies, VLP vaccination after DNA priming induced HIV-1 neutralizing antibodies to tier 1 viruses that are easy to neutralize and to a select number of tier 2 viruses that are much harder to neutralize. The tier 2 viruses include HIV-1 subtype B viruses, which are common in Europe, Australia, and the Americas, and subtype C viruses, which are predominant in southern Africa, China, and India. HIV-1 subtype B and C viruses account for more than 50% of AIDS worldwide. The study also demonstrated that HIV-1 VLPs formulated without an adjuvant were as potent as an adjuvanted protein subunit vaccine with respect to eliciting neutralizing antibody responses to both tier 1 and tier 2 viruses.

Dr. Richard Compans, chairman of the department of microbiology and immunology, Emory University School of Medicine, and senior investigator on the research team, said, "This vaccine approach differs from most others now in clinical trials in that VLPs are designed to produce neutralizing antibodies. Such antibodies have the potential to block the HIV infection process at its earliest stage."

Dr. Beatrice Hahn, professor of medicine at the University of Alabama at Birm
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