Can’t Pass It On

People on effective HIV antiretroviral medication, can’t pass HIV on to our sexual partners. When we use our HIV medication to control (or suppress) HIV, people living with HIV can’t pass it on to our sexual partners (even without condoms).

This is also called by a few other names such as Treatment as Prevention (TasP) or Undetectable equals Untransmittable (U=U).

This is an effective HIV prevention strategy used by the majority of people living with HIV to reduce the levels of the HIV virus in our bodies, prevent the transmission of HIV, protect our own health and the health of our partners. Along with the strategy of starting medication immediately after diagnosis, today people living with HIV are active players in protecting and preventing HIV transmission.

The Science Stuff

Research over the past 20 years has proven that using HIV medication to control HIV is a significant strategy for the majority of people living with HIV who can maintain an undetectable viral load (UVL).

There are two large main pieces of research, the 2016 PARTNER study, and the 2019 PARTNER 2 study, which have both shown ZERO HIV transmission from a HIV positive person (taking their HIV medication as prescribed) to their sexual partner who doesn’t have HIV, even without using condoms.

For a majority of people living with HIV who take our HIV medication as prescribed, when we suppress our HIV viral load to an ‘undetectable’ level (UVL) for at least six months, we cannot pass HIV to our sexual partners (even without condoms). When a person living with HIV has a viral load of less than 200 copies/mL, for at least 6 months, they are considered to have an undetectable viral load (UVL), and cannot pass HIV onto their sexual partners.

It is only one of many HIV prevention strategies used by people living with HIV such as condom use, serosorting, strategic positioning, viral load monitoring, and negotiated safety options. The World Health Organisation (WHO) and UNAIDS also recognise HIV medication to be a key sexual health strategy to prevent HIV transmission.

Around 5% of people living with HIV cannot suppress their HIV viral load to ‘undetectable’ levels. Some of these reasons include genetics, treatment resistance factors, immuno-compromised systems, or various multi-morbidity health conditions. There are also times during our lives where we cannot maintain viral suppression for a range of different reasons.

Viral Blips

It’s common for people on antiretroviral therapy to experience a ‘viral blip’. This is a short term increase above undetectable level.

The Partners Study showed there was no transmission of HIV to their partners if they experienced a viral blip between 20-200 copies per ml.

Get Support

If you are living with HIV and want to talk about HIV medications, the Can’t Pass It On campaign or about Treatment as Prevention, please call Positive Life on (02) 8357 8386 or 1800 245 677 (freecall) or email

More reading

Q&A on the PARTNER study

HIV & Treatment as Prevention (TasP) – also known as U=U

People living with HIV and Treatment as Prevention (TasP) – what’s it mean? – published April 2017

When zero means zero: a new freedom when living with HIV – published August 2016

The Opposites Attract Study (2012-2015) – published September 2014

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