Researchers this week will begin testing an experimental HIV vaccine on 24 human volunteers in South Africa, a country where more than one in 10 people is infected with the AIDS-causing virus.
The treatment, which is also being tested in the United States, is one of about two dozen potential vaccines being tested by some 12,000 human volunteers in experiments around the world. It is the only one that contains genetic material from the HIV strain most prevalent in South Africa, researchers said Monday.
Some 4.7 million South Africans, roughly 11 percent of the population, are infected with HIV. An estimated 600 to 1,000 South Africans die every day from AIDS-related complications.
The vaccine contains parts of a weakened strain of Venezuelan equine encephalitis and a harmless gene from a South African HIV strain.
By entering human cells, scientists hope it will stimulate the production of antibodies that will fight off AIDS infections, and also train specialized cells — dubbed killer T-cells — to identify and eliminate infected cells after someone contracts the virus.
The first human trials are aimed at establishing the safety of the drug and are expected to last two years. If successful, they will be widened to take in more volunteers and determine the vaccine’s effectiveness.
AIDS is notoriously successful at beating the body’s immune system and so far has resisted every vaccine tried.
In February, VaxGen Inc. reported that the world’s most advanced human vaccine experiment — involving 5,000 volunteers — had failed.
Tucker predicted it would be at least 10 years before an effective vaccine was ready for distribution.