On Feb. 15, 2023, it was reported that a 53-year-old man in Germany had become at least the third person with HIV to be declared clear of the virus after a procedure that replaced his bone marrow cells with HIV-resistant stem cells from a donor.

The stem-cell technique involved was first used to treat Timothy Ray Brown, often referred to as the Berlin patient. In 2007, he had a bone marrow transplant, in which those cells were destroyed and replaced with stem cells from a healthy donor, to treat acute myeloid leukemia.