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Rare individuals suppress HIV without treatment
Scientists are studying a small group of people whose immune systems naturally keep HIV in check, potentially unlocking new pathways to a cure. Among them was Loreen Willenberg, a 71-year-old landscape designer from Sacramento, California, who tested positive for HIV in 1992 but lived for decades without medication or symptoms. Willenberg, who died in April 2026 after battling stage four cancer, became a focal point for research into how the body can eradicate the virus on its own.
Elite controllers: A scientific anomaly
Willenberg was one of an estimated 0.5% of HIV-positive individuals classified as "elite controllers." These rare individuals maintain undetectable viral loads without antiretroviral therapy. Researchers, including Xu Yu of the Ragon Institute, found no trace of viable HIV in Willenberg's cells even after her immune system was suppressed during cancer treatment. Yu declared at the 2025 International AIDS Society conference that Willenberg was likely "completely rid of HIV," a groundbreaking revelation.
The biology behind natural suppression
Elite controllers like Willenberg possess unique genetic traits that enhance their immune responses. Their CD8+ T cells, a type of white blood cell, are particularly effective at inhibiting HIV. Studies show these cells can trap the virus in "gene deserts"-inactive regions of DNA where HIV cannot replicate. This mechanism offers a blueprint for a functional cure, where the virus remains dormant and harmless.
"The intact viruses are there, but they're parked in an area which doesn't allow them to do anything anymore."
Xu Yu, Ragon Institute
Post-treatment controllers: A parallel discovery
Research has also identified "post-treatment controllers," individuals who initially required antiretrovirals but later maintained viral suppression after stopping medication. The Visconti cohort in France, a group of 30 such patients, has lived without treatment for over two decades. Their natural killer cells, part of the innate immune system, may play a key role in keeping HIV at bay.
Gender disparities in immune response
Women make up the majority of elite controllers, with studies suggesting their innate immune systems are better equipped to combat HIV. Despite this, most HIV cure trials have historically focused on men. Yu notes that women have a "two-to-five-fold higher probability" of becoming elite controllers, underscoring the need for more inclusive research.
Toward a cure: Therapeutic vaccines and beyond
Scientists are exploring therapeutic vaccines to activate natural killer cells in HIV reservoirs, such as lymph nodes and the gut. Christina Thobakgale of the University of the Witwatersrand highlights the challenge of reaching hidden viral pockets. "Natural killer cells that are highly active and efficient might help flush out and destroy these hidden pockets of HIV," she says.
A legacy of hope
Willenberg remained optimistic about the potential of elite controller research to end the HIV epidemic. "If my contributions have advanced the science, then that has been quite an honor," she said months before her death. While she did not live to see the epidemic's end, her story continues to inspire efforts to develop a cure for the 40.8 million people living with HIV worldwide.
