U.S. researchers report successfully testing two candidate vaccines that may eventually be used together 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. tested two possible HIV vaccines with the hope of producing an immune response in healthy, uninfected adults.
One candidate was a plasmid DNA-based vaccine expressing genes from three dominant HIV subtypes, and the second used recombinant adenovirus serotype 5 (rAd5) as a vector to deliver similar HIV strains.
Both vaccines were tested in healthy, uninfected adult volunteers. The DNA vaccine was found safe and well-tolerated. By the 12th week following immunization, 97.5 percent of vaccinees experienced positive CD4 T cell responses and 40 percent experienced positive CD8 T cell responses.
The recombinant vector vaccine was also well-tolerated but higher doses led to adverse events such as pain and fever. By the fourth week following immunization, 93.3 percent of vaccinees experienced positive CD4 T cell responses, and 60 percent experienced positive CD8 T cell responses.
The study is detailed in the Dec. 15 issue of The Journal of Infectious Diseases.
Copyright 2006 by United Press International
