The first component is a simple DNA vaccine, which contains proteins found in the AIDS virus, telling the immune system to remember them and fight back if infection occurs. A second booster shot, based on a virus used in a smallpox vaccine, is given weeks later to mimic viral infection and prompt an immune response. The simple DNA vaccine is in its first phase of testing for dangerous side effects on both Kenyans and Britons, while initial tests of the smallpox vaccine are being conducted in England. If proven safe, the two vaccines will be tested together. Then, the combination vaccine, which has proven effective when used on monkeys, will be tested to see whether the duo actually wards off HIV in humans.
Relief workers teach prevention.
Scientists consider a vaccine the best hope for stopping the AIDS epidemic, and several possible vaccines are in testing. But research has been slow with many failures. Scientists have cautioned that they don't know if this or other vaccines would work in humans and that further study will take years. No vaccine has proven absolute in preventing the HIV infection, although some have been able to keep the virus in check at nearly undetectable levels for several months, in monkeys. A vaccine may be the only hope for fighting AIDS in Africa.