Nearly six years into the search for an AIDS vaccine, researchers at the Johns Hopkins School of Medicine say they are battling not only scientific obstacles but also the reluctance of people to roll up their sleeves for experiments.
While gay men remain loyal to the effort, the Hopkins vaccine program has been frustrated in its attempt to recruit women and blacks -- two groups that would help scientists evaluate vaccines across racial and gender lines.
People invoke a variety of reasons not to participate, according to recruiters.
Many wrongly believe the vaccine could give them AIDS. Some feel AIDS is a distant epidemic that doesn't touch them. Some resent the looming presence of Hopkins in a community wracked with poverty. Others don't want to spend the time.
Many mistrust medical experimentation.
In the black community, mistrust is rooted in the harrowing example of the Tuskegee, Ala., incident, an experiment in which federal health officials denied treatment to a group of Southern blacks suffering from syphilis. The experiment started in the 1930s and lasted 40 years, well past the discovery of antibiotic cures.
Dr. Jack Lambert, clinical director of AIDS vaccine studies at Hopkins, said reluctance to get involved is not limited to the inner city.
"As soon as people hear the word AIDS, they just turn the other way," he said.
"If I go up to college students and ask if they want to get involved in a vaccine trial, the first reaction is, 'I don't want to get AIDS,' " Dr. Lambert said.
Since 1988, about 300 people have enrolled in vaccine trials at Hopkins.
In Baltimore, where blacks have born the brunt of the AIDS epidemic, 21 percent of the vaccine volunteers are black. Women constitute 29 percent of the volunteers.
The director of AIDS vaccine trials at the National Institute of Allergy and Infectious Diseases looks at the record and sees progress. Dr. Patricia Fast concedes that recruitment among blacks has been difficult -- only 9 percent of the volunteers nationally are black -- but she notes that 44 percent are women and more than half are heterosexual.
20 hours recruiting
"When they say [at Hopkins] that it isn't easy to motivate people, I can't argue with them," Dr. Fast said. "But are they successful in recruiting volunteers who are not white and gay? Yes."
Carol Hilton, who directs recruitment at Hopkins, estimates that in recent years she has spent 20 hours recruiting every qualified volunteer. This has lengthened the time it takes to conduct trials.
Some experiments designed to gauge vaccine safety, for instance, lasted two years rather than one, she said. In addition, researchers had to content themselves with half the intended number of volunteers for a trial focusing on a high-risk group -- healthy partners of infected individuals.
Toughest of all, they said, has been the recent attempt to test a vaccine on a group that risks a double blow from the epidemic: pregnant women infected with the human immunodeficiency virus. Researchers hope a vaccine might prevent a woman from infecting her baby and delay her own progression to full-blown acquired immune deficiency syndrome.
Despite seven months of recruitment and the promise of free medical care, only one woman has signed up.
"People are always condemning you for not involving women in research," Ms. Hilton said. "So now that we're involving women, where are they? Being a woman, I don't understand it, and being a mother, I don't understand it. How do we get across that we have this epidemic and the kids are at risk?"
In all, 10 pregnant women have enrolled at five medical centers that make up a consortium testing AIDS vaccines under a grant from the National Institutes of Health. The goal is 24 volunteers.
Besides Hopkins, the centers are Vanderbilt University in Nashville, Tenn.; the University of Washington in Seattle; Rochester University in Rochester, N.Y.; and the University of St. Louis.
Finding an effective AIDS vaccine has proved a huge scientific challenge. For now, researchers are testing vaccines to determine whether they are safe and capable of stimulating the immune system. Some of the vaccines do cause the immune system to make antibodies, but there is no evidence this will counter an onslaught of HIV.
Scientists believe they are still a few years away from giving vaccines to large groups of people who are considered at risk -- the sort of tests necessary to see whether a vaccine works. Few scientists believe they will have a proven vaccine before 2000.
Compared with the scientific hurdles, recruiting volunteers for today's small trials may seem a simple task. It isn't. When the vaccine trials began, researchers relied on white, gay men who were eager to contribute to a chapter of medical history and possibly stop the carnage in their community.