San Francisco Chronicle - Wednesday, February 3, 1999
David Perlman, Chronicle Science Editor

Even though an international group of physicians has volunteered to test such a live- virus human AIDS vaccine, Harvard scientists are warning that their monkey vaccine has caused the disease in some animals and has killed at least one.

The idea of using a weakened form of HIV, the virus that causes human AIDS, has intrigued vaccine researchers for years, and experiments at Harvard with a virtually identical virus that causes disease in monkeys appeared to make at least some of the animals immune to the simian version of AIDS.

Now, however, another team of Harvard researchers has found that a group of infant and adult monkeys vaccinated with a live but disabled form of the simian AIDS virus developed AIDS.

Dr. Ruth Ruprecht, of Harvard's Dana- Farber Cancer Institute, reports in the current issue of the journal Nature Medicine that she and her colleagues vaccinated eight newborn monkeys and 16 adults with the disabled virus. Six of the infants developed AIDS and two showed early signs that their immune systems were badly damaged, while levels of active virus rose among four of the adults, and one of them died of AIDS.

Disabled viruses have been used to make vaccines against many diseases. Smallpox no longer threatens the world because a live-virus smallpox vaccine has eliminated every known reservoir of that virus throughout the world. The oral polio vaccine, also made from a live but weakened strain of the polio virus, has practically eliminated that paralyzing disease.

Scientists can weaken a disease-causing virus either by removing some of the proteins from its outer coat or by removing one or more of the genes that enable it to reproduce once it has invaded the body and taken over the genetic machinery of the immune system cells it penetrates.

The monkey vaccine that was tested for three years starting eight years ago was made by removing a single gene known as the "nef" gene from the simian AIDS virus. It was developed by Dr. Ronald Desrosiers and his colleagues at Harvard's New England Regional Primate Research Center.

But when the preliminary results from Ruprecht's team were first circulated last year, Desrosiers and his group said they had not given up on the concept and would try weakening a human version of their live-virus AIDS vaccine even further by removing four of the viral genes instead of only one.

One of Desrosiers' colleagues, Dr. John Sullivan of the University of Massachusetts Medical School, suggested recently that such a vaccine might be tested on terminally ill cancer patients who volunteered for the trial, but that idea has spawned an ethical debate.

"Our study indicates that it is not safe to conduct human tests of AIDS vaccines made from live, weakened viruses," Ruprecht said. "There is a real risk of contracting AIDS from the vaccine itself."
990203
SC990202

Always watch for outdated information. This article first appeared in 1999. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 1999. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .