NEW YORK – As scientists struggle to find a vaccine to prevent infection with the AIDS virus, a study in mice suggests hope for a new approach – one that doctors want to test in people.

The treated mice in the study appeared to have 100 percent protection against HIV. That doesn’t mean the strategy will work in people. But several experts were impressed.

“This is a very important paper (about) a very creative idea,” says the government’s AIDS chief, Dr. Anthony Fauci. He didn’t take part in the research.

David Baltimore and colleagues at the California Institute of Technology reported the new results in mice online Wednesday in the journal Nature. They hope to test the approach in people in a couple of years.

Another research team reported similar success in monkeys in 2009 and hopes to start human tests even sooner.

A traditional vaccine works by masquerading as a germ, training the body’s immune system to build specific defenses in case the real germ shows up. Those defenses are generally antibodies, which are proteins in the blood that have just the right shape to grab onto an invading virus.

Scientists have identified antibodies that neutralize a wide range of HIV strains, but they’ve had trouble getting people’s immune systems to create those antibodies with a vaccine.So why not just give a person genes for those proteins? The genes can slip into cells in muscle or some other tissue and make them pump out lots of the antibodies.

Ordinary mice don’t get infected with HIV, which attacks the immune system. So the research used mice that carried human immune system cells.

Baltimore’s team used a harmless virus to carry an antibody gene and injected it once into a leg muscle. The researchers found that the mice made high levels of the antibody for more than a year.

The results suggest lifetime protection for a mouse, Baltimore said, although “we simply don’t know what will happen in people.”