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AIDS advance reported

Scientists have succeeded in improving the way the body fights the virus that causes AIDS _ a discovery could open the door to new ways of treating the disease. In a study by the Army's Walter Reed Research Institute in Rockville, Md., researchers have found that by administering an experimental vaccine to 30 men and women infected with HIV _ the AIDS virus _ they were able to prompt the immune systems of most of those in the group into mounting a much more sophisticated counterattack against the virus than they otherwise would have.

Scientists familiar with the study, published in today's New England Journal of Medicine, say it is too early to know whether the type of response elicited by the Walter Reed group actually will help HIV-infected people in the long run to survive the ravages of the disease.

The health of those who developed the novel immune system response did not appear to deteriorate over the course of the eight-month study, but that is too short a period from which to draw conclusions about efficacy, the scientists said.

However, the study's results appear to counter the long-standing and pessimistic conviction of many AIDS researchers that there is little that can be done to improve upon the human immune system's own _ and ultimately unsuccessful _ battle against the HIV virus.

"I don't want to give anyone the idea that we have any proof that this will work," said Robert Redfield, the Walter Reed AIDS researcher who headed the study. "But my gut feeling is that this technique will play an important role in the future in the management of HIV."

"This is not a breakthrough," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. "It is far from a breakthrough. But it is a very interesting observation that needs to be pursued."

The theory behind the new study is simple. During the first few years after becoming infected with HIV, the immune system of most people manages to keep the virus in check. At some point, however, the virus overwhelms the body and the onset of AIDS begins.

This raises the possibility that if some way could be found to boost the body's immune system, the initial success against HIV could be stretched from several years to a much longer period, and perhaps indefinitely.

The conventional wisdom among virologists has held that any attempt to improve on the immune system's own response to infection is pointless: that the defense the body mounts the first time it sees an invading virus is the best it is capable of mustering.

Redfield and a number of other prominent AIDS researchers, including polio vaccine pioneer Jonas Salk, have challenged this notion. In preparing his study, Redfield reasoned that what makes HIV so deadly is that it manages to fool the human immune system, cloaking its identify so cleverly that the body never gets a good enough look at it to wage a successful, long-term battle.

"It is to the virus' advantage to distract the immune system, to present only those aspects of itself to the immune system that are not critical to its survival," Redfield said.

Working on this assumption, Redfield and his colleagues took a group of HIV-infected people and injected them with tiny pieces of what they believed was the most important part of the AIDS virus, a region called GP 160.

Like any vaccine, the preparation administered by Redfield did not contain any parts of the AIDS virus that cause disease or pose a health risk. It simply looks like the virus, tricking the body into responding as it did when it originally faced with the AIDS virus. In this case, however, Redfield and his colleagues were hoping the material they were injecting would give the body a more honest view of the AIDS virus, to elicit the strongest possible reaction against HIV.

Presented with a more accurate view of the AIDS virus, the body responded differently: 19 of the 30 patients in the group developed new kinds of antibodies to the AIDS virus and an unusual proliferation of the kinds of white blood cells that are critical in fighting the virus. In addition, the health of the 19 seemed to stabilize, at least during the study.

Redfield and Fauci, who wrote an accompanying editorial on the study, were quick to point out that many questions remain unanswered.

For one thing, the experiment did not test whether the volunteers lived longer or healthier lives.

"We look forward to more conclusive proof of safety and therapeutic efficacy in controlled trials that are now in progress," said Franklin Volvovitz, president of MicroGeneSys, the Meriden, Conn., company that manufactured the vaccine.

_Information from Reuters was used in this report.