A study presented at the ninth International AIDS Conference on HIV Science in Paris on Tuesday revealed that treatment can ensure zero odds of sexual transmission of the HIV virus.
The large-scale research was led by Austrian experts from the Kirby Institute, following almost 350 homosexual couples with one person HIV positive having treatment.
"If a person is diagnosed and quickly gets on to treatment, then they quickly become non-infectious and that is great news for HIV prevention more broadly, because it's an absolutely key part of us trying to turn this epidemic around and drive infections down," chief investigator Professor Andrew Grulich told Austrian media.
In the study, each couple reported their sexual activity to the research team, and the HIV negative partners were regularly tested to diagnose any new infections.
The result showed that all the couples had sex almost 17,000 times without condoms over four years, and no new infections were reported except three cases affected by sex outside of the relationships.
Current HIV treatment works by suppressing the level of virus, so that immune system damage is halted and even reversed. When treatment is consistently taken, the virus levels will drop so that they become undetectable in the blood.
However, uncertainty remains. Professor Grulich said the general advice is that a person should wait at least three to six months to confirm they are non-infectious by a blood test.
Besides, an experimental HIV vaccine regimen which was well-tolerated and generated immune responses against HIV in an early-stage clinical trial was presented at the conference on Monday.
The trial called APPROACH involved nearly 400 volunteers in the United States, Rwanda, Uganda, South Africa and Thailand.
The new vaccine is based on "mosaic" vaccines designed to induce immunological responses against a wide variety of HIV subtypes responsible for HIV infections globally.
