Clinical Trials to Begin on HIV Vaccine That Uses Horse Virus

American and South African researchers are preparing for the first human trials of an HIV vaccine derived from HIV subtype C, the "most common" HIV strain in southern Africa, and Venezuelan Equine Encephalitis, a mosquito-borne virus that affects horses, the London Independent reports. Carolyn Williamson, a virologist from the University of Cape Town, explained that the "coat" of VEE, which is found in North and South America, is being used to deliver the HIV vaccine. "[A]s [the HIV in the vaccine] doesn't have all the ingredients to replicate itself, it is rendered not infectious," she said. However, "[o]nce delivered, the machinery is in place to churn out volumes of HIV protein needed to get an immune response, which in turn will hopefully protect against infection," she added. The final plans for the initial stage of human testing are "in place" and candidates who are "free of HIV, not likely to contract it and in good health" are being sought for the randomized double-blind study, which is scheduled to begin in March. The trial will contain a placebo arm (Clarke, London Independent, 8/13).

Molecular Discovery to Aid Vaccine Research
In other vaccine development news, the "discovery" of the structure of IgG1 b12, an antibody that attaches to the HIV protein gp120 and "neutralizes" the virus, could assist vaccine researchers in developing a new approach to fighting HIV, Reuters Health reports. Researchers explained in the Aug. 10 issue of Science that b12 is shaped like a "Y" or a "T," and that one of the "finger-like" extensions fits into the gp120 molecule, "effectively block[ing] other portions of the virus surface that are needed to cause infection." The researchers said vaccine and drug developers can use this information to design drugs that also fit into the gp120 "glove" to fight infection. Knowing the design will also aid in developing vaccines that "enable the body's virus-fighting antibodies to recognize this critical region of the HIV surface," they added. "(Our hope is) that the vaccine design community would utilize this structural information to produce an effective vaccine," Dr. Ian Wilson of the Scripps Research Institute in La Jolla, Calif., said (Boggs, Reuters Health, 8/10).