Recognizing MeritResearch: David Vlahov
is recognized for work
with HIV, drug users
David Vlahov remembers the sinking feeling he felt upon
hearing the news that he had been awarded a five-year grant to
study the mysterious disease affecting intravenous drug users.
The National Institute on Drug Abuse made the grant to Vlahov and
his research team, hoping they could find out whether this
disease was the same one affecting gay white men.
The year was 1985, and scientists did not yet know that the HIV virus caused AIDS.
"There was so much work ahead of us," Vlahov says.
Vlahov, now professor of epidemiology at the School of Public Health, and his colleagues calculated that in order for their results to be statistically significant, a minimum of 640 HIV-positive drug addicts would have to be enrolled as a cohort. That meant that somewhere between 3,000 to 5,000 active drug users must be interviewed: a sobering thought.
"We, of course, had heard the conventional wisdom about drug users," Vlahov says. "They're difficult to recruit, they're not interested in their health, they'll never stay in touch with your study. So, when this grant got approved, instead of champagne we considered sending out for cold compresses."
Although somewhat daunted by the task, the researchers established the ALIVE study (an acronym Vlahov prefers to the somewhat winded original name) and set about forming an advisory board made up of former and active drug users. The board pointed out pitfalls and taught the scientists how to design a study that addicts would comply with. (One tip: Don't set up your clinic at the hospital; it's seen as a hostile environment.) Then, from February 1988 to March 1989, the researchers interviewed and tested 2,960 drug users from Baltimore's streets and clinics, 24 percent of whom were HIV-positive.
"Of those 24 percent," says Vlahov, "90 percent came back for their blood test results and enrolled in the program. And, after nine years, we still have about a 95 percent follow-up rate. So much for the conventional wisdom."
Now, in recognition of his decade-long response to the dual public health crises of drug abuse and AIDS, Vlahov has received a MERIT Award from the National Institute on Drug Abuse at the National Institutes of Health.
The MERIT--Method to Extend Research in Time--Award aims to provide long-term support to outstanding investigators in order to eliminate the burden of preparing grant proposals for the same work. Researchers do not apply for the MERIT Award; they are chosen by the NIH and its advisory councils. Award recipients can extend their grant for three to five years by submitting a progress report and abstract of their research plans.
Vlahov's MERIT award will extend his ongoing study of the natural history of HIV infection for 10 more years.
"The incidence of HIV infection among intravenous drug users continues to rise," notes Vlahov. "And when you consider that the incubation time of HIV can be a decade or two, 10 more unbroken years of study are particularly welcome."
The data generated by the ALIVE study are being put to practical use. In 1994, Baltimore City used the data to convince legislators that a needle-exchange program would save lives. Vlahov and his collaborators are also credited with discovering that addicts, when they were attempting to sterilize their needles with household bleach, were not keeping the needles submerged long enough to inactivate the HIV virus. The HIV virus must be in contact with bleach for at least 30 seconds to be destroyed, but the drug users were immersing their paraphernalia for an average of just 16 seconds.
Besides looking at what can prevent the spread of AIDS, Vlahov and his colleagues are trying to tease out the effects such risk factors as poor nutrition, co-infection with other diseases, initial viral load, differences in HIV strains, as well as genetic factors, will have on the course of the HIV infection. In addition, the MERIT study will permit investigation of the long-term effects of clinical care on the use of drugs that suppress HIV.
The ALIVE study has also been examining the question of why some IDUs develop AIDS soon after infection and others take years, even decades. Avenues being investigated include characteristics of both the virus and of the immune system, genetics, nutrition and personal habits. In collaboration with the SHARE study in Baltimore and cohort studies in New York, Rome, Amsterdam and Marseilles, the ALIVE investigators are comparing the natural history of HIV infection by gender, race and risk group.
The researchers have learned for instance that once addicts find out they are HIV-seropositive, they usually stop or cut back on high-risk behaviors. On the other hand, if the drug user still tests HIV-negative he or she may tend to think, "I must be doing something right," and continue to pursue high-risk activities.
Contributing to Vlahov's success has been an ability to oversee both behavioral and biological studies of the disease. While carrying out his own epidemiologic studies, he has been able to entice immunologists and bench-based virologists into joining his studies of drug abuse and AIDS. Five scientists collaborated with him when he began the project; 22 now participate, and the group's multifactor approach has garnered 11 NIH research grants.
Members of the MERIT project team
Vlahov views the MERIT Award as recognition for the many co-investigators who have made this project possible, including James Anthony, David Celentano, Homayoon Farzadegan, Neil Graham, Donald Hoover, Cynthia Lyles, Richard Markham, Alvaro Munoz, Kenneth Nelson, Walter Royal, Richard Semba, Alice Tang and Xiaofang Yu, as well as the dedicated clinical, laboratory and analysis staffs.
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