The New World of AIDS: The Hunt for a Vaccine
Advances Inject Hope Into Quest for Vaccine
Wednesday, September 3, 1997
ST. LOUIS -- Inside a small and nearly windowless downtown medical clinic, Tim Lynch rolls up one sleeve of his T-shirt and looks straight ahead, trying not to notice the stainless steel needle being unsheathed beside him.
Lynch, who is 35 and gay, is not infected with HIV, the virus that causes AIDS. But if all goes well in the next few weeks his body will behave very much as though it were.
St. Louis University vaccine researcher Robert Belshe leans forward, slides the needle into Lynch's arm and pushes the plunger on the syringe, propelling about a million specially modified viruses into the man's muscle.
They are canarypox viruses, which cause disease in birds but are harmless in people. Each one has been genetically engineered to contain three extra genes that are normally found only in HIV. The goal is to introduce some of the hallmarks of HIV to Lynch's immune system, so he can build up a SWAT team of antibodies and white blood cells capable of fighting off a real infection, should one ever occur.
Lynch is one of thousands of healthy people in the United States who have agreed to lease their immune systems to science for a period of months or years, as part of the quest to develop an AIDS vaccine. It is a quest that has proven exceedingly and unexpectedly difficult.
AIDS vaccine researchers have endured so many disappointments in the past decade that some began to think their mission was impossible. HIV has shrugged off dozens of experimental formulations that almost certainly would have felled lesser viruses. Meanwhile, progress has been hampered by a lack of investment from private vaccine developers and a federal research program criticized as lacking in leadership.
Yet a new, if cautious, optimism has emerged among many AIDS vaccine researchers in the past year or so. Using salvaged bits of information from otherwise failed experiments, scientists have been developing a picture of what a successful AIDS vaccine would look like -- then building and testing vaccines along those lines and getting them into human trials. Increasingly, the results of those trials have been offering up more good news than bad.
Political and economic will may also be on the rise. This summer, President Clinton declared a national goal of producing an effective AIDS vaccine within 10 years. He also called for the quick creation of a vaccine research center at the National Institutes of Health.
"It's still not going to be easy," said Patricia Fast, associate director of the vaccine and prevention research program of the National Institute for Allergy and Infectious Diseases, the NIH branch that holds primary responsibility for the federal war against AIDS. "But the idea that it's impossible," Fast said, "is gone."
The need for an AIDS vaccine has never been greater. Although new and potent drugs are proving remarkably effective in many patients, scientists are concerned that those benefits may not last forever. And the new drugs are largely unavailable or unaffordable in developing countries, where 95 percent of the world's new cases are emerging.
"We'll never end this epidemic unless we have a vaccine," said Sandra Thurman, chairman of the White House Office of National AIDS Policy.
Recent progress notwithstanding, the art and science of making a vaccine remains frustratingly inexact -- and the testing process remains fraught with dangers. In Lynch's case, for example, no one knows whether the engineered bird virus might someday make him or his fellow volunteers ill. Also worrisome: Animal studies have suggested that AIDS vaccines may in some cases speed, rather than slow, the progression of AIDS in vaccinated people who eventually become infected with HIV.