U=U stands for Undetectable equals Untransmittable.

What Does U=U Mean?

U=U means that a person on HIV treatment with an undetectable HIV viral load cannot transmit HIV to another person. UK guidelines state that HIV clinicians should discuss U=U with their patients, so this should not be new to people living with HIV.

How is that Possible?

Viral load is the term used to describe the amount of HIV in the blood. The higher the viral load, the greater the risk there is to a person’s own health and illness through HIV. Viral load is also related to the risk of HIV transmission through sex. The aim of HIV treatment is to bring the amount of virus down to undetectable levels. Having an undetectable viral load means that the HIV treatment has effectively reduced the virus to an amount that is so small it cannot be quantified. When a person is undetectable this is good for their own health and it also means that there is too little of the virus in sexual fluids for it to be transmitted.

How Can we be Sure About U=U?

There have been two large studies called PARTNER 1 and PARTNER 2. These studies included couples where one partner was HIV positive and undetectable on HIV treatment and the other partner was HIV negative. PARTNER 1 followed gay and heterosexual couples who had sex without condoms more than 58,000 times. PARTNER 2 followed gay male couples who had sex without condoms more than 77,000 times. The outcome of these studies was that there were zero linked transmissions of HIV. Evidence has now meant that U=U has become widely and confidently accepted and is endorsed by the British HIV Association (BHIVA) as well as equivalent international organisations.

What’s Needed for U=U to Work?

Guidelines recommend that a person has an undetectable viral load for at least six months before guaranteeing the protection of U=U.

U=U is dependent on maintaining an undetectable viral load. For the person living with HIV, this means taking daily HIV medication as prescribed. Good adherence is key to U=U. Viral load monitoring is part of the routine testing that happens when a person attends their HIV clinic appointments.

What Does U=U Mean in Practice?

The PARTNER studies looked at heterosexual couples including HIV positive men and women as well as gay couples, meaning that U=U applies to all. It also included acts of oral, vaginal and anal sex and passive and active roles, meaning that U=U applies to different types of sexual situations.

The bottom line is that if you are HIV+, take treatment and maintain an undetectable viral load, you can have sex knowing that you won’t pass HIV on to your sex partner. If you were using condoms with a sex partner solely to stop the transmission of HIV, then this is no longer a reason to keep using them. However, U=U doesn’t protect against other sexually transmitted infections or prevent pregnancy, which may be a reason that people opt to keep using condoms.

What is the Significance of U=U?

U=U is extremely important in challenging the stigma that surrounds HIV, stigma that is often fuelled by a fear of transmission.

Bruce Richman, the founder of Prevention Access Campaign and Undetectable = Untransmittable, said:

“First, we focus on internal stigma because there are millions of people worldwide who are suffering because they don’t know U=U,” he says. “But then there is the external stigma as well. U=U changes the way we see ourselves, but it also changes the way other people see us: the way we’re treated in clinics and healthcare settings, the way policy decisions are made about us in employment, housing and education. Stigma is such a challenge but because U=U absolutely changes the definition of what it is to live with HIV, it dismantles that stigma.

“We now have an unprecedented opportunity to do that. And that changes everything.”