Unpacking undetectable = untransmissible (U=U)

The undetectable=untransmissible (U=U) campaign is a popular, wide-spread and fantastic message for all people living with HIV!

It is a campaign with the message that a person living with HIV who is on antiretroviral treatment, and has been able to maintain viral suppression with an ‘undetectable viral load’ (UVL) for 6 months, has zero risk of passing HIV onto our sexual partners.  This is exciting news for all people living with HIV and for those we love, bang or fuck.

As a man living with HIV for over 30 years, I know what it’s like to live in a time when we were heavily stigmatised as the ‘vectors of disease’. I know what it’s like to live in fear of passing on a potentially deadly infection in a time when there were no treatments or treatments with dreadful side effects. In less than half my lifetime, thanks to tireless researchers, HIV is a manageable chronic health condition like diabetes or heart disease, and I am free to love, bang or fuck anyone without fear of passing on HIV. Knowing ‘treatment as prevention’ (TasP) works and there’s zero risk of transmitting HIV to our sexual partners has been profound. The U=U message is liberating and powerful.

However, being undetectable or having a UVL, isn’t universally applicable. ‘Undetectable’ means different things in different jurisdictions.

Back in 2008, doctors in Switzerland noticed that some apeople living with HIV didn’t pass HIV to their HIV negative partners even if they were not using condoms. These doctors were the first to make a statement about their observation also known as the ‘Swiss Statement’ which was that a person taking antiretrovirals maintaining viral suppression could not pass HIV to their sexual partners. At the time, some clinicians thought this was irresponsible and there was considerable backlash to the statement.

Three very rigorous studies, the Partners Study 1 and 2 and the Opposites Attract Study soon followed, which all supported the Swiss Statement. These three studies used a viral load (VL) test to measure the quantity of HIV in the blood. This test used a sensitivity of measuring the existence of HIV in the blood above 200 copies/mL or more. Based on this test, a person with a VL of less than 200 copies/mL is considered to have an undetectable viral load (UVL).

As the years rolled by, science has refined the sensitivity of VL tests and it’s now possible to measure the number of copies of HIV in the blood down to as low as 20 copies/mL, especially in developed countries like Australia or the United States where we can afford this more precise equipment.  In some resource-poor jurisdictions, the sensitivity of the testing equipment, if available, remain at 200 copies/mL.

The question that needs to be asked is where do we set the bar for ‘undetectable’ now there’s different availability and standards of VL tests being used around the world? Part of the answer is in the Partners Study 1 &2 and the Opposites Attract Study.

All three studies used the VL sensitivity of 200 copies/mL. Within these studies it was noted that while all the participants were undetectable below 200 copies/mL, some people living with HIV within these studies registered what is known as a ‘viral blip’ on more sensitive tests e.g. at 20 or 60 copies/mL. Technically, these people were detectable using the more sensitive tests, yet they were under 200 copies/mL and still undetectable by all three studies.

This reality causes a lot of anxiety and confusion for many and their partners, when they see a viral blip based on using the more sensitive VL tests. People who are undetectable suddenly see a VL load based on this more sensitive test and U=U no longer seems to hold up for them. Of course, despite this tests sensitivity, these people living with HIV are still uninfectious.

What does this mean if undetectable tests fall below 10 copies m/L?? As more sensitive tests are developed, many people living with HIV who are undetectable reading this right now would be detectable under that kind of testing standard, even though they cannot pass on HIV. This highlights a significant crack in the U=U messaging along with other questions of how U=U relates to other concerns like combination antiretroviral therapy (cART) interactions with other medications, treatment resistance, ageing, fears of antiretroviral therapy (ART), HIV in breast milk or people who inject substances.

There is very little to explain to the average person living with HIV what a viral blip is or what it means. Is the test detecting HIV or a broken inert piece of HIV or even another virus at these more sensitive levels of testing?

In NSW, people living with HIV have achieved so much together as a community. As we continue living full lives with HIV, we need powerful messages based on rigorous science that unites the Body Positive without dividing or excluding some of us based on increasingly sensitive tests.

If we talk about U=U, the reality remains that not everyone is undetectable at the more sensitive levels of testing. It would be accurate, and more inclusive of all PLHIV who are maintaining viral suppression, to say you cannot pass on HIV (untransmissible) if you have a UVL below 200 copies/mL. This would also reduce the confusion and anxiety for everyone when we are discussing risk for HIV transmission.

Another question that arises is how high above 200 copies/mL remains ‘safe’? We don’t have any research to accurately give us a conclusive answer.

This is a conversation to have with our HIV clinicians and discuss results while asking for answers from our doctors and HIV specialists. The clear and undeniable message is that treatment as prevention (TasP) works. People living with HIV who maintain viral suppression (below 200 copies/mL), by taking their treatment, antiretroviral medications, as prescribed are at zero risk of passing on HIV to their sexual partners.

If you want support to explore what the U=U message means for you, call Positive Life on (02) 8357 8386 or 1800 245 677 (freecall) or email contact@positivelife.org.au