The woman whose immune system appeared to defeat HIV without medication

For more than three decades, Loreen Willenberg was known to HIV researchers as a remarkable anomaly. The 71-year-old landscape designer from Sacramento, California, tested positive for HIV in 1992, but the virus remained latent in her body and she lived for decades without receiving medication for the infection.

Willenberg was considered one of the world’s best-known “elite controllers,” a rare group of people whose immune systems can keep HIV under control without medical intervention. Researchers estimate that about 0.5% of people living with HIV belong to this group.

Her case became even more remarkable after she was diagnosed with stage IV cancer in 2022. Although treatment suppressed her immune system, researchers still could not detect HIV in her cells.

At the 2025 International AIDS Society conference, researcher Xu Yu said Willenberg had probably cleared HIV completely from her body after extensive testing failed to find evidence of the virus.

Willenberg died from cancer in April 2026, but researchers say her case could provide important clues for developing new treatments and potentially a cure for HIV.