A game-changing trial has shown that rates of HIV infection can be slashed by treating actively gay men with an anti-viral drug when they are healthy.
The Proud study, conducted in England, provides the first evidence that prophylactic HIV treatment is highly effective in a real-world setting.
It showed that pre-exposure to the HIV drug Truvada can reduce the risk of infection in men-who-have-sex-with-men by as much as 86 per cent.
Previous research had suggested that prophylactic treatment might cut HIV infection rates but it was unclear whether such an approach would work in practice.
The new study of 545 participants divided the men into two groups, one of which was to be given Truvada immediately and the other a year later.