An American research team reported that it has potentially cured a woman of HIV using a novel treatment. The procedure to treat the woman is called a haplo-cord transplant and was performed by a team at New York-Presbyterian Weill Cornell Medical Center in New York where the patient was treated. She’s not only HIV-free, but the transplant cured her cancer as well.

According to The New York Times, the scientists announced on Tuesday that the woman of mixed race appears to be the third person ever to be cured of HIV using umbilical cord blood to boost the immune system and resist the virus. The woman was diagnosed with HIV in 2013 and with leukemia in 2017, says NBC News. The challenge was to treat both her HIV and cancer, so the two-pronged haplo-cord method was used.

The woman received umbilical cord blood from an infant donor who was HIV-resistant. They also gave her blood from a close relative to give her body temporary immune defenses while the transplant took hold. In haplo-cord transplants, the addition of stem cells from an adult donor hastens “the early engraftment process and renders the transplant easier and safer,” said Dr. Koen van Besien, of Weill Cornell. This therapeutic process is meant to replace an individual’s immune system with another’s, treating their cancer while also curing their HIV.

“We estimate that there are approximately 50 patients per year in the U.S. who could benefit from this procedure,” van Besien said of the haplo-cord transplant’s use as an HIV-cure therapy. The woman’s 2017 transplant was successful, and she has been in remission from her leukemia for more than four years. Three years after her transplant, doctors discontinued her HIV treatment, and she continues to be virus-free.

Cord blood does not need to be an exact match to the recipient, and is more widely available than adult stem cells typically used in bone marrow transplants. Most registry donors are Caucasian so the fact that a donor can be a partial match has the potential to help dozens of Americans with both HIV and cancer each year, according to scientists.

Doctors prefer to say she is in HIV remission, rather than cured, but hope as time passes there will be no future resurgence of the virus.

“The fact that she’s mixed race, and that she’s a woman, that is really important scientifically in terms of the community impact,” said Dr. Steven Deeks, an expert in AIDS at the University of California, San Francisco who was not involved in the work.

HIV can be controlled by powerful antiretroviral drugs, but a cure is key in ending the pandemic, says the Times. Approximately 38 million people live with HIV globally, and 73% receive treatment. A bone marrow transplant is not a realistic option for these patients because of its risk and brutal side effects, so it has only been offered to HIV patients who also have cancer and have run out of options.

By contrast, the woman treated in New York left the hospital 17 days after her procedure and did not develop serious side effects, such as host versus graft disease, which is also a possibility in bone marrow transplants.

The scientists believe that using stem cells from newborn cord blood works well because the cells may be more adaptable, says van Besien.

“Umbilical stem cells are attractive,” said Dr. Deeks. “There’s something magical about these cells and something magical perhaps about the cord blood in general that provides extra benefit.”