An end to AIDS is in sight © Getty Images

An end to AIDS is in sight

Conclusive results of an eight-year study find that men on an antiretroviral HIV treatment have a zero risk of passing on the virus to sexual partners.

An antiretroviral treatment developed by researchers at University College London (UCL) and the University of Copenhagen has reduced the possibility of passing on the virus that causes AIDS to zero.


The study, named PARTNER2, involved nearly 1,000 European gay couples in which one partner was HIV positive and the other HIV negative. Over the course of the eight-year study the couples reported having sex without the use of condoms nearly 80,000 times. None of them was found to pass on the virus to the HIV negative partner. The researchers estimated that based on the type and frequency of sexual contact, the treatment prevented around 500 HIV transmissions.

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“Our findings support the message of the international U=U campaign, that a suppressed viral load makes HIV untransmittable. This message has been endorsed by more than 780 HIV organisations in 96 countries and can help end the HIV pandemic by preventing HIV transmission, and tackling the stigma and discrimination that many people with HIV face,” said lead researcher Prof Alison Rodger, who is based at UCL’s Institute for Global Health.

Antiretroviral drugs work by stopping a virus from replicating in the body, allowing the nervous system to recover and preventing further damage. The measure of the number of viral particles present in a given person’s bloodstream is known as a viral load and is expressed as the number of copies of the virus found in one millilitre of blood. For anyone on antiretroviral treatment therapy, the aim is to keep the viral load as low as possible.

In the PARTNER2 study, the treatment kept the viral loads of the HIV positive participants at fewer than 200 copies per millilitre, which is known as an ‘undetectable viral load’ and is the point at which the virus cannot be transmitted. When not on antiretroviral treatment, viral load amongst HIV positive patients can reach several millions.

“Increased efforts must now focus on wider dissemination of this powerful message and ensuring that all HIV positive people have access to testing, effective treatment, adherence support and linkage to care to help maintain an undetectable viral load,” said Rodger.


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