New Vaccine Treatment for AIDS
Vaccine Recharges Anti-HIV Immunity in Monkeys
Dec. 23, 2002 -- A bold new kind of vaccine may one day let people quit their AIDS drugs. Monkeys infected with a deadly AIDS virus stay well after getting the treatments.
Reporting in the advance online issue of Nature Medicine, Wei Lu of Rene Descartes University and colleagues report stunning results from a new kind of vaccine. The vaccine uses a type of cell -- dendritic cells or DCs -- commonly found in the skin. These cells have several functions, but their main job is to grab foreign substances and turn them in to the immune system. This begins a chain reaction that starts a powerful immune attack on similar substances.
Wu's team loaded up DCs with a killed AIDS virus. They then injected the cells into monkeys infected with the same virus. This virus normally causes a rapid AIDS-like disease that quickly kills monkeys. But when the infected monkeys got the vaccine treatment, they didn't die. They didn't even get sick -- at least for the 34-week study period.
Instead, they mounted fierce immune attacks. Most vaccines make the immune system do one of two things: make antibodies or make germ-killing cells. The DC vaccine elicited both kinds of immune responses.
"Therapeutic approaches designed to generate strong HIV-specific cellular and [antibody] immunities using inactivated-virus-loaded DC vaccines might result in long-term immunologic control of chronic HIV disease," Lu and colleagues write.
In commentary published along with the study, Bruce Walker, MD, director of AIDS research at Massachusetts General Hospital, says the findings are surprising and unexpected. A major issue, he says, is how long the vaccine-stimulated immune responses will keep the AIDS virus under control.
"If the approach is confirmed in monkeys and successfully adapted in humans, it may represent a major new therapeutic approach to HIV," he writes.