The man has no signs of active infection four years after he stopped taking antiretroviral drugs. “We don’t think there’s a functional virus present,” says Björn Jensen at Düsseldorf University Hospital.
The “Düsseldorf patient” tested positive for HIV in 2008. In 2011, he developed leukaemia that was treated with chemotherapy, but it came back the following year. So, in 2013, the blood stem cells in the man’s bone marrow that give rise to immune cells – including the cancerous ones – were killed off by chemotherapy and then replaced with donor blood stem cells.
Crucially, doctors found a donor with a mutation that disables the CCR5 receptor that HIV uses to infect immune cells.