Human trials begin for an AIDS vaccine developed by Emory researchers.

Racing against 15,000 new HIV infections a day

A human clinical trial has begun at several sites around the country to test a promising HIV/AIDS vaccine developed by a team of Emory researchers. This is the first time the entire vaccine has been tested in humans.

Using an innovative “prime-boost” strategy to combat the virus, the vaccine consists of two inoculations of a DNA vaccine, which prime the immune system to recognize HIV, and two doses of a booster vaccine to heighten that response. The vaccinations are spread over two months.

The vaccine was developed by a scientific team led by Professor Harriet Robinson, chief of microbiology and immunology at the Yerkes National Primate Research Center, faculty member of the Emory Vaccine Center, and chair of the GeoVax Scientific Advisory Board.

“It is really exciting and a major landmark to have this second trial under way,” says Robinson, who first began researching AIDS vaccines in the early 1990s. “This trial is the first to evaluate the prime with the boost. We anticipate that safety will be excellent and that we will see strong immune responses. If this is born out, we will be in a strong position for initiating further large-scale dosing trials and then the all-important efficacy trial.”

More than a million people are living with HIV/AIDS in the United States and about forty million worldwide. More than three million died from AIDS in 2005, according to the World Health Organization. With an average of fifteen thousand new infections every day, researchers such as Robinson feel an urgent call to halt the epidemic.

Antiretroviral drugs can control the virus for those who can afford them, says Robinson, but “the real solution for the world is a vaccine.”

A prototype of Robinson’s vaccine was successful in containing a challenge virus and preventing progression to AIDS in rhesus macaque monkeys at Yerkes. Twenty-two of twenty-three monkeys given the DNA vaccine and booster failed to develop AIDS symptoms, even after exposure to high levels of the virus.

The vaccine produces the three major proteins contained in HIV but not the intact virus, so it can’t cause the disease.

In 2003 and 2004, the DNA vaccine was tested in a group of HIV-negative volunteers to evaluate its safety. Based on successful results, the U.S. Food and Drug Administration approved additional trials to test both parts of the vaccine together.

The current trials will evaluate the complete vaccine in HIV-negative volunteers at several sites in the HIV Vaccine Trials Network, including the University of Alabama at Birmingham, Saint Louis University, the University of Maryland, and Vanderbilt University.

The vaccine technology was licensed to GeoVax, an Atlanta biotechnology company founded by Robinson, President and CEO Don Hildebrand, and Emory to further develop, manufacture, test, and evaluate the vaccine.

“Our vaccine appears to have the best level and longest duration of protection of any AIDS vaccine tested so far in nonhuman primates,” says Hildebrand, a microbiologist who came from the biopharmaceutical industry to head GeoVax.

More than thirty AIDS vaccines are in early stages of human clinical trials around the world. —M.J.L.

To learn more about Harriet Robinson, GeoVax, and the development of the vaccine, go to



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