As of mid-2024, seven people have been medically recognized as cured of HIV or in sustained long-term remission after treatment. That number stands against the 40.8 million people currently living with HIV worldwide. Every confirmed cure so far has come through a bone marrow or blood stem cell transplant, a procedure so risky and rare that it is only performed on patients who already need one for a life-threatening blood cancer.
Who Are the Seven Cured Patients?
The first person cured of HIV was Timothy Brown, known publicly as the Berlin Patient. In 2007, he received a stem cell transplant for leukemia from a donor who carried a rare genetic mutation. Brown remained HIV-free without medication for over a decade until his death from recurrent leukemia in 2020. His case proved that a cure was biologically possible and opened the door for similar attempts.
Since then, four more patients have followed a nearly identical path: the London Patient, the Düsseldorf Patient, the City of Hope Patient, and a seventh case presented at the AIDS 2024 conference, a 60-year-old German man who received his transplant in 2015. All were living with both HIV and a blood cancer, all received stem cell transplants from donors carrying the same protective genetic mutation, and all stopped taking antiretroviral medication afterward without the virus returning.
The remaining two cases broke the mold in important ways. The New York Patient, a woman of mixed race, received a transplant using umbilical cord blood rather than adult donor cells. And the Geneva Patient achieved sustained remission using a donor who did not carry the protective mutation at all, something researchers previously thought was necessary.
How These Transplants Eliminate HIV
HIV enters immune cells through a surface protein called CCR5, which acts like a doorway on the outside of the cell. Roughly 1% of white Europeans carry two copies of a mutation called CCR5-delta 32, which produces a version of this protein so malformed that the cell’s internal quality control system destroys it before it ever reaches the surface. People with this mutation simply have no door for HIV to walk through.
In five of the seven cured patients, the transplanted stem cells came from donors homozygous for this mutation. After the transplant replaced the patient’s immune system, the new cells were effectively immune to HIV. Over time, the virus lost its ability to survive in the body.
The Geneva Patient’s case suggests the transplant itself may do much of the work regardless of the mutation. His new immune cells were fully susceptible to HIV infection, yet the virus remains undetectable nearly three years after he stopped medication. Researchers at the Institut Pasteur believe the graft-versus-host reaction, where the transplanted immune cells aggressively attack the recipient’s tissues, may have been thorough enough to destroy the hidden reservoirs of virus-infected cells throughout the body. His ongoing immunosuppressive treatment for those same graft-versus-host reactions may also be preventing any remaining virus from reactivating.
Why This Can’t Be Scaled to Millions
A stem cell transplant is one of the most dangerous procedures in medicine. Before the transplant, patients undergo intensive chemotherapy to wipe out their existing immune system. For days to weeks afterward, they have almost no functioning immune defense. For someone already living with HIV, this creates a compounding risk of severe infection.
Even when the procedure goes well, complications are common and serious. Graft-versus-host disease, where the donor’s immune cells attack the recipient’s organs, can become chronic and affect the intestines, liver, and skin. Long-term side effects include organ damage, bone and muscle weakness, infertility, cataracts, and an increased risk of secondary cancers. The procedure carries a meaningful risk of death.
Then there’s the donor problem. Finding a stem cell donor requires matching specific immune markers between donor and recipient. The odds of finding a donor who is both a close match and carries two copies of the CCR5-delta 32 mutation are extremely low. The mutation occurs in approximately 1% of white people and is essentially absent in other ethnic groups, making this approach even less accessible for the majority of people living with HIV globally.
The New York Patient’s case offers a partial workaround. Umbilical cord blood can successfully engraft with only a partial immune marker match, which expands the pool of potential donors significantly. A research initiative called IMPAACT P1107 has been pre-screening cord blood units to build a bank of CCR5-delta 32 donor cells specifically for non-white individuals. But cord blood transplants still require chemotherapy and carry the same fundamental risks.
Functional Cure vs. Sterilizing Cure
Scientists distinguish between two types of cure. A sterilizing cure means every last HIV-infected cell has been eliminated from the body. A functional cure means the virus may still be present at very low levels, but the immune system controls it indefinitely without medication, with no detectable viral load, no loss of immune function, and no risk of transmitting the virus.
It is not entirely clear which category some of the seven cured patients fall into. The Geneva Patient, for instance, may still harbor some infected cells, but his immune system appears capable of keeping any remnants in check. For practical purposes, both types of cure mean the same thing for the patient: life without HIV medication and without the disease progressing.
A small number of people living with HIV achieve something similar naturally. Known as elite controllers, they make up fewer than 1% of all people with HIV, with estimates ranging from 0.15% to 1.5%. Their immune systems suppress the virus to undetectable levels without any medication. They are not considered “cured” in the traditional sense, since the virus still exists in their bodies, but they offer a biological blueprint that researchers are studying closely.
Gene Therapy as a Possible Path Forward
The most promising route to a scalable cure is gene editing. Rather than replacing the entire immune system through a transplant, the idea is to use tools like CRISPR to cut HIV’s genetic material out of infected cells or to disable the CCR5 receptor on a patient’s own immune cells. A Phase 1 clinical trial of a therapy called EBT-101, which delivers a CRISPR-based system through an intravenous injection, is currently underway. No results have been published yet.
Gene therapy would bypass the need for a donor, eliminate the risks of chemotherapy and graft-versus-host disease, and potentially work for people of any ethnic background. But the technology is still in its earliest stages of human testing, and it remains unknown whether editing cells inside a living person can clear enough of the viral reservoir to achieve lasting remission. For now, the seven people who have been cured represent extraordinary individual cases rather than a replicable treatment, each one a proof of concept that the virus can be permanently defeated.