No Progress, No Panic

By David Brand

"We now know more about this virus than perhaps any virus one wishes to discuss," declared Dr. Samuel Broder of the National Cancer Institute. But as researchers presented their findings at the International AIDS Conference in Washington last week, it became clear that there is no immediate hope of discovering a vaccine to inoculate people against the AIDS virus. And few new drugs are on the horizon that might alleviate or cure the disease. Said Dr. Harold Jaffe, chief AIDS epidemiologist at the Centers for Disease Control in Atlanta: "The strides made in the molecular biology of the virus are just phenomenal. But that hasn't yet translated into something we can use to stop it."

Hopes for an experimental vaccine sagged when Duke University's Dr. Dani Bolognesi and NCI's Dr. Robert Gallo, a co-discoverer of the AIDS virus, reported that tests on chimpanzees had failed. Chimps, one of man's closest relatives, are considered critical to vaccine research. The idea of a vaccine is to trick the body into producing specific antibodies that can attack the invading virus. The research team had vaccinated six chimps with proteins from the outer shell of the AIDS virus, then injected them with live virus to test the vaccine's effectiveness. But within three weeks the chimps became infected.

Other possible vaccines are being tested on chimps by Bristol-Myers and the Institute for Immunological Disorders in Houston. Both have applied for permission to test vaccines on humans. Testing is already being done by Dr. Daniel Zagury of Paris' Pierre and Marie Curie University. Zagury included himself among twelve healthy people who received an experimental vaccine made up of a portion of the AIDS virus inserted into a larger, usually harmless virus called vaccinia. They also received a booster shot of their own cells that had been treated with the vaccinia. The volunteers, he reported, showed signs of antibodies to the AIDS virus. Nonetheless, warned Zagury, "we do not want to give false hopes."

NCI's Gallo revealed that he and his co-workers had discovered in ten Nigerian patients a new strain related to the AIDS virus. Together with an earlier discovery by French scientists of a second AIDS virus in West Africa, which is now being found in Europe and Brazil, this increases the family of related AIDS viruses. The existence of multiple strains further complicates the development of blood tests and vaccines for AIDS. Gallo insisted, however, that "we shouldn't panic because it is the original AIDS virus that is causing the epidemic."

There has also been little progress in developing AIDS drugs that interfere with viral reproduction. The only drug approved by the FDA is azidothymidine, or AZT. An experimental drug, ribavirin, made by ICN Pharmaceuticals of Costa Mesa, Calif., seems to be less effective than had been claimed. Dr. Andrew , Vernon, a member of a study group at Johns Hopkins University, reported that in a 28-week experiment, 217 male pre-AIDS patients who took ribavirin showed no significant benefits.

Peptide T, another promising substance for curbing the virus, received mixed reviews. Last December, Neuroscientist Candace Pert of the National Institute of Mental Health reported that the chemical, a synthetic portion of a protein on the AIDS virus that helps it bind to cells, seemed to prevent the virus from entering cells. In May the FDA approved clinical trials, and last week Oncogen, a Seattle biotechnology company, announced that its researchers had confirmed Pert's findings. But Dr. William Haseltine, a virologist at Harvard's Dana Farber Cancer Institute, said neither his laboratory nor six others around the world had been able to reproduce Pert's results.

Not all was gloomy. Abbott Laboratories has developed a new blood test that, because it directly indicates the presence of the AIDS virus, can immediately show infection. Current tests, because they detect only antibodies, may take weeks to months to indicate the presence of the virus.

With reporting by Dick Thompson/Washington