The New York Times - August 4, 1984
Lawrence K. Altman

Researchers from the Centers for Disease Control and the National Institutes of Health said yesterday that both animals injected with a virus and others given blood taken from a patient became infected with AIDS as a result.

It is the scientists' hope, since more extensive research has now been made easier, that a greater understanding of the disease and eventually a successful treatment for AIDS will result. The disease cripples the body's immune system, leaving it vulnerable to organisms that ordinarily do not harm unaffected people.

Since AIDS was first reported in 1981, several research teams have repeatedly tried to infect animals with specimens taken from humans with AIDS. But the attempts were unsuccessful.

Dr. Donald P. Francis, who heads the AIDS laboratory team at the Centers for Disease Control, said in an interview that he "did not know why" the two teams had succeeded now when they and others had not in the past.

Evidence Points to Virus

Transmission of the disease to a primate strengthened the case that a virus causes AIDS. Two such viruses belonging to the retroviruse family are believed to be implicated.

The discovery of one called LAV was reported in May 1983 by researchers at the Pasteur Institute in Paris. The finding of another called HTLV-3 was reported in April by researchers at the National Cancer Institute in Bethesda, Md. Both research groups have said they believe the viruses are the same.

The successful infections of the chimpanzees, described in the centers weekly report, resulted from two different approaches. The one done at the disease centers in Atlanta relied on the LAV virus discovered in France; the other done in San Antonio by researchers at the National Institutes of Health and Southwest Foundation for Biomedical Research relied on blood taken from an AIDS patient in the United States.

Injections of Virus

The Atlanta experiments began last March 6, shortly after Dr. Jean-Claude Chermann flew there from the Pasteur Institute with samples of the LAV virus, Dr. Francis said. Working with Emory University's Yerkes Regional Primate Research Center in Atlanta, the centers scientists inoculated LAV virus into two chimpanzees that had no evidence of infection with retroviruses.

The researchers took additional steps to increase the likelihood of infecting the chimpanzees with AIDS. They immunized the two animals against tetanus, diphtheria and pneumococcal infections to stimulate their immune systems. The scientists also removed from the chimpanzees samples of the type of blood cell called lymphocytes that are attacked by AIDS, infected the lymphocytes with LAV in the laboratory and injected them back into the chimpanzees.

Antibodies Developed

After four months, the two chimpanzees developed antibodies against the LAV and laboratory evidence of AIDS infection. However, neither of the animals has yet become ill.

In the other study, two chimpanzees received transfusions of human plasma from a patient with lymphadenopathy syndrome - a condition, characterized by swollen lymph glands, believed to be an early form of AIDS. These two chimpanzees later showed evidence of infection with the HTLV-3 virus. One of these animals developed generalized swollen lymph glands at the same time that it developed antibodies against the HTLV-3 virus.

When AIDS was first reported, epidemiologists at the Centers for Disease Control created a strict but arbitrary definition of a case of AIDS. Such definitions are standard in medical investigations of diseases of unknown origin and may change when additional facts are learned.

Many doctors believe that because the definition is so narrow, there are more people suffering from AIDS than the 5,394 reported to the Atlanta diseases center as of July 30. Of that total, 2,462 have died.

Discovery of LAV and HTLV-3 has enabled researchers to develop laboratory tests to measure antibodies that the body produces against each agent. However, researchers are trying to determine the meaning of the presence of such antibodies. It is not clear whether they represent active infection or whether they are left in the blood by an earlier infection that the individual overcame without becoming ill.

Learning to Increase Protection

By taking biopsies and blood samples from infected chimpanzees before and after experimental infection with AIDS, researchers hope to be able to get a better understanding of the meaning of the presence of antibodies. In particular, Dr. Francis said, they would like to determine what substances are most effective in stimulating the largest amount of protective antibodies.

Researchers would also be able to measure the amount and types of antibodies the animal produces in response to injection of various experimental vaccines. However, the presence of such antibodies does not necessarily correlate with the ability to protect against the disease.

Thus Dr. Francis said he expected that researchers will be able to inject the AIDS virus into animals that have received experimental vaccines to determine if those vaccines truly protect against the disease. For ethical reasons such studies are not done in humans.

Dr. Francis emphasized that although the chimpanzee research may clear the way for vaccine testing, it would take years before such a vaccine could be made available to the public.

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