WASHINGTON, Oct 19 (AFP) - A new vaccine, made from DNA, combined with immune-boosting proteins, controlled the AIDS virus in early tests, keeping the virus to undetectable levels in infected monkeys, according to a report in the journal Science published Friday.

According to researchers the vaccine, made of DNA including two genes from the AIDS-causing virus, did not prevent the innoculated monkeys from getting infected, but kept them from getting sick, despite being infected with a particularly deadly strain of the virus.

The study suggests that a vaccine could boost the immune system, "dramatically changing the clinical outcome of an AIDS virus infection," said Dan Barouch of Beth Israel Deaconess Medical Center and Harvard Medical School, the study's lead author.

Researchers injected eight rhesus monkeys with the vaccine and then infected them with a virulent strain of the virus that causes AIDS that would normally make them sick within weeks and kill them within months.

After 140 days, the innoculated monkeys were alive and well, and the virus was at undetectable levels in their blood.

Researchers believe that keeping the viral levels low could slow the spread of the disease among high-risk populations.

In a related article also published in Science, Xuefel Shen and Robert Siliciano at Johns Hopkins University School of Medicine note that this kind of vaccine could "substantially decrease" the rate of infection in humans and AIDS deaths worldwide, particularly in areas where drug therapies are unavailable.

"We can't bring drugs to all the people of the world, but you can imagine bringing a vaccine," David Baltimore, chairman of AIDS vaccine research at the National Institues of Health told The New York Times.

But researchers said that the results of this early study on monkeys cannot be directly related to humans.

"We need to be a little bit cautious in extrapolating to humans," said Gary Nabel, also of the National Institutes of Health. But, "by and large, this is good news."

In an attempt to boost the vaccine's effects, it was paired with proteins that are known to improve immune response.

The "vaccine plus" proved very effective, with all of the innoculated monkeys surviving.

On the contrary, all of the uninnoculated monkeys got sick and half died during the 140 days of the experiment. Among the monkeys which received only the vaccine, the effect was mixed, and two of the animals developed advanced disease.

Researchers do not know how long the effects of the vaccine last, but Barouch suggested that multiple immunizations may be needed. The team is planning a long-term study to see if the disease can be held off long-term.

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