WEDNESDAY, Dec. 10 (HealthDay News) -- Researchers report that a treatment under development appears to stop the equivalent of the AIDS virus in monkeys.

Nine rhesus macaque monkeys infected with a virus known as SIV underwent treatment and remain alive eight months later. The treatment appears to work by preventing virus cells from fooling the immune system.

There's no guarantee that the treatment will work in people. But if it's effective in humans, the treatment could allow patients to avoid taking AIDS drugs for the rest of their lives, said study co-author Rama Rao Amara, an assistant professor at Emory University's Yerkes National Primate Research Center.

"If you wake up and realize you don't have to take a pill, it's a big step forward," he said. In addition, he said, current AIDS drugs are expensive and have serious side effects.

Existing AIDS drugs do have benefits: They're often effective and have allowed patients to live normal lives. However, they can't always keep up with the AIDS virus, which evolves quickly and can become immune to current treatments.

"The virus changes and then these drugs don't work after some time," Amara said.

In the new study, Amara and colleagues injected nine monkeys with an antibody that blocks a kind of "don't kill me" signal that cells infected with simian immunodeficiency virus (SIV) send to immune cells.

When the SIV-infected cells emit the signal, "the killer cell thinks, 'You are not my enemy. You're my friend,'" Amara said. But when the signal is blocked, the killer immune cells can do their job and wipe out the virus.

The researchers gave four injections of the antibody to the monkeys over 10 days and then watched to see what happened.