Blueprint of a cure: The rare people who are invulnerable to HIV

Scientists are studying the few extraordinary individuals whose bodies seem able to naturally defend themselves from HIV in the hope of finding new cures.

For more than three decades, Loreen Willenberg, a 71-year-old landscape designer living in Sacramento, California, was known to HIV scientists as an intriguing anomaly.

Willenberg tested positive for HIV in 1992. Yet, instead of overwhelming her immune system and ultimately killing her, the virus remained suppressed in her body. She was able to live an ordinary life for many decades – despite never receiving any medication for the disease.

"My doctors have always told me that my immune response to HIV was very unique," she told me in an interview in August 2025. "For many years, they didn't know for sure, but they knew I was different."

Willenberg, who passed away in April this year, was arguably the world's most famous "elite controller", a term given to a tiny proportion of HIV positive individuals whose bodies somehow keep the virus under wraps without interventions. Approximately 0.5% of all people infected with HIV make up this extraordinary group. And scientists believe they hold the key to helping millions of people around the world beat HIV.

Willenberg's own survival with the virus was the more remarkable given that, in 2022, she was diagnosed with stage four cancer, which spread from her lungs to her brain. She responded well to treatment: the surgery and intense courses of medication shrank her tumour. By suppressing her immune system to fight the cancer, however, the medication should have allowed the HIV lurking in her body to resurface and spring to life.

But when researchers scoured Willenberg's cells for the presence of HIV, they still found no detectable trace of the virus.

That's why, at the 2025 International Aids Society conference, Xu Yu, a professor of medicine at the Ragon Institute of Mass General Brigham, MIT and Harvard who has hunted extensively for signs of HIV in Willenberg's body, stood before a room on scientists and made a dramatic statement. Willenberg, she declared, was probably completely rid of HIV.

This remarkable news was bittersweet. A few months later, Willenberg succumbed to the cancer she had been battling, passing away in April 2026. The legacy she has left behind, however, is profound – proof that one of the most devastating infectious diseases to emerge in the past century can be beaten.

"Some elite controllers like Loreen, they just don't have any viable virus [in their bodies] anymore," says Yu. "After we analysed billions of cells, there's really nothing." This is particularly significant, she says, as it implies that it is possible, in extremely rare circumstances, for the immune system to eventually eradicate HIV on its own. 

There is similar optimism surrounding another extensively studied elite controller from Argentina, an anonymous woman in her thirties known as the Esperanza (Spanish for "Hope") patient, who is also thought to be potentially cured of HIV too. 

Buoyed by these remarkable stories, scientists like Yu have been delving deeper into the biology of elite controllers. They believe these people's remarkable immune systems hold clues to developing next-generation treatments for the 40.8 million people living with HIV.

In the coming years, this may help point towards a cure.

Typically, when a person is initially infected with HIV – known to science as the Human Immunodeficiency Virus – it begins to spread rapidly through their body. By replicating by splicing its genetic material into the DNA of cells, the........

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