So far, there still is no vaccine that can protect against AIDS. One reason, scientists say, is because of the unusual way HIV attacks a cell, binding to its target site at an odd place that allows it to escape the wrath of the antibodies that typically scrub the blood of dangerous invaders. Another reason is HIV's protein "coat," which seems capable of changing its chemical composition and disguising HIV's true nature from immune responses. But as tricky as it is, the human immunodeficiency virus is bound to be susceptible to some kind of attack by the immune system. That's why AIDS researchers keeping searching for a vaccine.
Doctors at Walter Reed Army Hospital have found a vaccine that triggered strong responses in 19 of 30 volunteers infected with the HIV in field trials begun in 1989. In a recent Baltimore medical conference, they disclosed even greater success: provoking a response from those volunteers who initially showed no sensitivity to the vaccine with frequent "booster" shots. No one knows yet whether that will help these victims fight off the onset of full-blown AIDS, but even getting their immune systems geared up at all is a big achievement.
Now, Army doctors want to see how their test vaccine does with inner-city residents, who typically receive poorer health care and eat less nutritionally balanced diets than the initial subjects, all military personnel and dependents. Can the vaccine, made of genetically engineered HIV fragments, work as well for subjects drawn from the general population? A test involving 100 University of Maryland patients and another 100 from the rolls of Washington-area private physicians should find out.