The nonprofit International AIDS Vaccine Initiative (IAVI) hailed the start of a human trial in South Africa and the US to test AlphaVax Inc.'s candidate vaccine to prevent HIV/AIDS. This is the first AIDS vaccine trial ever conducted in South Africa, which has one of the world's highest HIV infection rates.

The vaccine candidate, named AVX101, is intended to protect people who are uninfected with HIV from becoming infected or going on to develop AIDS. It is tailored for the subtype of HIV most prevalent in South Africa, subtype C.

Volunteers in the US part of the trial are now receiving the vaccine candidate, with volunteers in South Africa to follow within eight weeks. Ninety six adult volunteers, 48 in each country, are sought for the trial.

Dr. Seth Berkley, President and CEO of IAVI, said: "South Africa joins other African countries, including Kenya, Uganda and Botswana, as a leader in the global search for a preventive AIDS vaccine. A vaccine is our best hope to end the spread of the epidemic." Each day, 15,000 people become infected with HIV, including thousands in sub Saharan Africa.

"AlphaVax's AVX101 AIDS vaccine candidate has been shown in preliminary laboratory studies to be promising. To know if the vaccine is effective, AVX101 must be tested in human trials-first in small trials like the one that has just begun in South Africa and the US, then in larger scale, multi year trials," Dr. Berkley said.

AVX101 is constructed so that there is no risk of it causing HIV infection or AIDS. Regulatory approval for the trial was granted last month by the South Africa Medicines Control Council, following clearance from the US Food and Drug Administration. The trial is sponsored by the HIV Vaccine Trials Network of the US National Institutes of Health. IAVI provided early financial and technical support for research into AVX101.

Two other preventive AIDS vaccine candidates are poised to start trials in South Africa, pending regulatory approval. One is being studied by IAVI, the University of Nairobi in Kenya and the University of Oxford and Medical Research Council in the UK. The second is being studied by Merck & Co. Inc. (MSD).