Progress Made in HIV Vaccine Development

U.S. researchers recently reported initial Phase I results from two vaccine candidates that successfully produced immune responses in healthy, uninfected adults. Eventually, the approach may be used to protect against HIV infection. Dr. Barney Graham and colleagues from the National Institutes of Health Vaccine Research Center, the Fred Hutchinson Cancer Research Center in Seattle, and GenVec Inc. performed the tests.

The first candidate was a plasmid DNA-based vaccine encoding genes from three dominant HIV subtypes. The vaccine was found to be safe and well-tolerated. At 12 weeks, 97.5 percent of those immunized experienced positive CD4 T cell responses and 40 percent had positive CD8 T cell responses.

The second candidate used recombinant adenovirus serotype 5 (rAd5) as a vector to deliver genetic clips from the same HIV subtypes as those in the first vaccine. This vaccine was also well-tolerated, but it led to adverse events including pain and fever at higher doses. By the fourth week, 93.3 percent of those immunized experienced positive CD4 T cell responses, and 60 percent had positive CD8 T cell responses.

The reports, "Phase I Safety and Immunogenicity Evaluation of a Multiclade HIV-1 DNA Candidate Vaccine," and "Phase I Safety and Immunogenicity Evaluation of a Multiclade HIV-1 Candidate Vaccine Delivered by a Replication-Defective Recombinant Adenovirus Vector," were published in the Journal of Infectious Diseases (2006;194:1650-1660 and 1638-1649).

Back to other news for December 1, 2006