Scientists are studying an HIV-positive Sacramento woman, whose immune system has remained intact, as part of a broach research effort aimed at uncovering clues to the AIDS virus that might lead to a cure.

Loreen Willenberg is one of 35 million people living with AIDS or HIV, but has remained healthy, had no symptoms, and taken no antiviral drugs since she was diagnosed 23 years ago, CBS News reports.

“In a clinical sense, I’m not progressing towards AIDS,” she said. “I’m not progressing towards the disease stage.”

Richard Pollard, M.D., says such long-term HIV survivors — who account for fewer than 1 in 100 people infected with the virus — may hold the secret to how to control AIDS.

“Their body has such an effective way of reacting to the virus that it’s hard to even detect that they’re virus positive,” Dr. Pollard said.

Over the past decade, Willenberg has participated in 13 studies designed to determine how and why they can resist the ravages of the AIDS virus.

“Finding the answer to that might lead to other kinds of research to try to develop techniques to make someone mimic these elite controllers,” said Dr. Pollard.