Scientists Study Rare Individuals Naturally Immune to HIV

Scientists are now focusing their research on a small, extraordinary group of individuals whose bodies are capable of defending themselves naturally against HIV. This rare phenomenon offers new hope for the development of a complete cure in the future. For more than three decades, Loreen Willenberg, a 71-year-old landscape designer from Sacramento, California, was a medical anomaly that attracted the world’s attention. Willenberg tested positive for HIV in 1992. However, instead of the virus crippling her immune system, HIV remained suppressed inside 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 International AIDS Society 2025 conference, Xu Yu, a professor of medicine from the Ragon Institute (a collaboration between Mass General Brigham, MIT, and Harvard), stated that Willenberg was most likely completely cleared of HIV. After analysing billions of cells, the research team found no trace of viable virus. In-depth research revealed that elite controllers have a highly robust adaptive immune system, particularly CD8+ T cells. These cells are capable of steering the HIV virus into segments of DNA known as gene deserts. Within these gene deserts, the HIV virus remains but is 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 it is ‘parked’ in an area that does not allow it to do anything,” explained Xu Yu. Besides T cells, recent research is also highlighting the role of Natural Killer (NK) cells. A study on the Visconti cohort in France showed that individuals who could control the virus after stopping treatment (post-treatment controllers) had gene variants affecting the behaviour of their NK cells. Christina Thobakgale from the University of the Witwatersrand, South Africa, noted that elite controllers possess more active and vigilant NK cells. These cells are capable of detecting and destroying hidden pockets of HIV in hard-to-reach locations such as the gut 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 passed away from cancer in April 2026, the scientific legacy she left behind is immense. Her survival proved that one of the deadliest infectious diseases of the last century can actually be defeated by the optimised power of the human immune system.