A fourth person in history has been cured of HIV after the patient was given a remedy for leukaemia and went into remission.
The 66-year-old man, who does not wish to be identified, received a stem cell transplant to treat the cancer type three and a half years ago - and US doctors are astonished.
The man, who was treated in California, had his cancerous red blood cells replaced with those of a donor in 2019. The donor’s cells happened to be resistant to HIV.
"When I was diagnosed with HIV in 1988, like many others, I thought it was a death sentence,” the man said in a statement.
"I never thought I would live to see the day that I no longer have HIV."
The man is thought to be the oldest patient of the four so far believed to have been cured in this way.
The first was the "Berlin patient" Timothy Ray Brown in 2007 while earlier this year, doctors in New York reported they had cured the first woman of HIV.
The result was celebrated at the International Aids Conference (IAS), which is happening this week in Montreal.
Doctors who presented the data ahead of the International Aids Society’s (IAS) 2022 meeting said the case opened up the potential for older patients with HIV and blood cancer to access the treatment, particularly as the stem cell donor was not a family member.
Describing a cure as the “holy grail”, Sharon Lewin, president-elect of the IAS, said the case provided “continued hope ... and inspiration” for people with HIV and the wider scientific community, although it was unlikely to be an option for most people with HIV due to the risks of the procedure.