Scientists Study Rare Individuals Naturally Immune to HIV

Scientists are now focusing their research on a small group of extraordinary individuals whose bodies are capable of naturally defending themselves against HIV. This rare phenomenon provides new hope for the development of total cure methods in the future.

For over three decades, Loreen Willenberg, a 71-year-old landscape designer from Sacramento, California, was a medical anomaly that captured global attention. Willenberg was diagnosed HIV-positive in 1992.

However, instead of the virus debilitating her immune system, HIV remained suppressed within her body without the aid of medication for decades.

Willenberg, who passed away in April 2026, was one of the most famous figures in a group known as ‘elite controllers’. This group comprises only about 0.5% of all people infected with HIV worldwide. Their bodies possess a unique ability to keep the virus under control without medical intervention.

At the 2025 International AIDS Society conference, Xu Yu, a professor of medicine from the Ragon Institute (a collaboration between Mass General Brigham, MIT, and Harvard), stated that Willenberg was likely completely clear of HIV. After analysing billions of cells, the research team found no traces of viable virus.

In-depth research reveals that elite controllers possess a highly robust adaptive immune system, specifically CD8+ T cells. These cells are capable of driving the HIV virus into DNA segments known as ‘gene deserts’.

Within these gene deserts, the HIV virus persists but remains trapped in a harmless, dormant state. Because it is located far from active genes, the virus cannot hijack the cell’s genetic machinery to replicate. “The intact virus is there, but they are ‘parked’ in an area that does not allow them to do anything,” explained Xu Yu.

In addition to T cells, recent research also highlights the role of Natural Killer (NK) cells. A study on the Visconti cohort in France showed that individuals capable of controlling the virus after stopping treatment (post-treatment controllers) possess genetic variants that influence the behaviour of their NK cells.

Christina Thobakgale from the University of the Witwatersrand, South Africa, noted that elite controllers have more active and vigilant NK cells. These cells are able to detect and destroy hidden pockets of HIV in hard-to-reach locations such as the intestines and lymph nodes.

Data indicates that women have a two to five times higher probability of becoming elite controllers compared to men. This is prompting scientists to delve deeper into the female immune system in future HIV cure trials.

Although Loreen Willenberg has passed away due to cancer in April 2026, the scientific legacy she leaves behind is immense. Her success in surviving proves that one of the deadliest infectious diseases of the last century can indeed be defeated by the power of an optimised human immune system.