Thomas Kahlert is one of 13 people reported cured of HIV, but that cure isn't one Ghanaians can get

The man known to scientists as the “second Berlin patient” has gone public. Thomas Kahlert, 62, has been off HIV treatment for eight years without the virus coming back, after a 2015 stem-cell transplant from a donor whose cells were not resistant to HIV. Researchers had not expected that combination to work.

Kahlert, who has worked at Berlin’s Charité university hospital for 38 years, spoke at the opening of BeCURE, the hospital’s new HIV cure research centre, and told the German news agency dpa he was doing “very well”. His HIV was picked up at a routine check-up in 2009, the kind of testing the Ghana AIDS Commission says too few men in Ghana are getting. In 2015 he was diagnosed with acute myeloid leukaemia, a blood cancer, and on 14 October that year he received stem cells from an unrelated female donor. He stopped taking his antiretroviral medicines in September 2018, a decision his doctors say he made himself.

What sets his case apart is the donor’s genetics. HIV gets into immune cells mainly through a receptor called CCR5, and a rare mutation known as CCR5-delta32 disables it; people who inherit two copies are considered naturally immune to HIV. The mutation is most common in northern Europe, where up to about 16 per cent of copies of the gene carry it, and it is close to absent in sub-Saharan Africa. The first Berlin patient, the American Timothy Ray Brown, was treated for leukaemia in Berlin with cells from a donor carrying two copies and became the first person known to be cured, and several of the cases since have relied on donors with the same double mutation. Kahlert’s donor had only one copy, which gives no such protection. So does Kahlert.

None of this is a treatment a person living with HIV in Ghana can ask for. The transplants behind these cases were given to treat cancers such as leukaemia and lymphoma, not HIV, and the US foundation amfAR describes them as high-risk procedures that are “only an option for a very small number of people with both HIV and certain blood cancers.” For everyone else the treatment remains antiretroviral therapy, which Ghana has been providing since 2003, and which health experts credit for the continued fall in AIDS-related deaths recorded in the Commission’s latest estimates.

Kahlert’s Charité team, led by Christian Gaebler, Samad Kor and Olaf Penack, published his case in the journal Nature this year. Across repeated tests they found no intact HIV in his blood, grew no virus from more than 130 million of his CD4 immune cells, and found none in tissue taken from his gut. They suggest the donor’s immune system may have attacked and destroyed the cells in which the virus was hiding, which they describe as a graft-versus-reservoir effect, and say the mechanism still has to be established. They call the outcome “durable HIV remission and potential cure” rather than a confirmed cure, and stress that it describes a single patient.

dpa reports that Kahlert is one of 13 people worldwide considered cured of HIV, against the 1.2 million people UNAIDS says acquired the virus in 2025 alone. amfAR lists 13 people cured or in possible long-term remission after stem-cell transplants, though it describes several of the more recent cases as likely or potential cures, and one, in Chicago, saw the virus return after treatment was stopped. Only one other person on that list, the Geneva patient, received donor cells without the mutation, and amfAR says it remains to be seen whether he has been cured. Brown died in September 2020 after his leukaemia returned.

In Ghana, the Commission’s estimates put new infections at 13,951 in 2025, down from 15,290 the year before, with Greater Accra recording the most, at 3,141, and national estimates put the number of children living with HIV at more than 18,000. Supplies of the medicines that keep people well have been under strain this year: in July the Commission had to reassure people that fresh antiretroviral medicines and test kits were weeks away, and in August the government cleared donor-funded HIV medicines that had been held up at Tema port.

According to dpa, Kahlert’s medical history will be used at BeCURE to help develop new treatment methods.