An experimental therapy has held back one man's HIV infection for 10 months, doctors have reported.
He was one of 18 people in a small trial testing injections of "broadly neutralising antibodies" - the natural weapons of the immune system.
They delayed the resurgence of the virus in other participants by around two weeks.
The findings are being presented at the ninth International Aids Society Conference on HIV Science in Paris.
The human body is inefficient at making antibodies that neutralise HIV.
Only one in five people infected with the virus develops them - and even then it takes many years and high levels of uncontrolled virus.
But more than 200 broadly neutralising antibodies have been documented, which doctors hope could be useful for both preventing and treating HIV.
James Gallagher BBC