“ It’s very, very clear that the risk is zero. ”
- Dr Alison Rodger
Lead author of PARTNER study
What is U = U? *
The evidence is in: If you are HIV+, take treatment and maintain an undetectable viral load, you cannot pass HIV on to your sex partner – with or without condoms. In short, when HIV is undetectable, it’s untransmittable. Those words are long so the shorthand is “ U = U ”.
What is an undetectable viral load?
Viral load refers to the amount of HIV in the blood of a person living with HIV. HIV treatment can reduce the amount of HIV in the blood to a level too low to be measured by a viral load test. At that point, a person’s viral load is said to be undetectable. For most people, this occurs after taking HIV treatment for three to six months.
What are the benefits of having an undetectable viral load?
Starting treatment as soon as possible after becoming HIV positive decreases a person’s risk of developing serious illnesses and allows people to live long, healthy lives. Having an undetectable viral load can also prevent HIV transmission.
How do I know if I’m undetectable?
The only way to know is to have regular viral load tests. If your viral load becomes detectable again, there may be a risk of HIV transmission. An ongoing detectable viral load may also indicate that your HIV treatment is no longer working properly. If your viral load becomes detectable, talk to your doctor.
Where’s the proof?
Since the introduction of combination therapy for HIV in the mid-1990s, there have been no confirmed reports of anyone with an undetectable viral load sexually transmitting HIV. Not one!
This conclusion is based on the overwhelming force of real world and research evidence including five major international research studies. These studies (see sidebar) showed that not a single HIV transmission occurred between serodiscordant* sex partners when the partner living with HIV was on treatment and had an undetectable viral load. (*Serodiscordant means one partner was HIV negative and one was HIV positive.) Combined, these studies tracked more than 150,000 condomless anal and vaginal sex acts – and there were ZERO transmissions of HIV.
The Prevention Access Campaign—an international coalition of HIV advocates, activists and researchers who are spreading the word that undetectable HIV is untransmittable—has turned this scientific evidence into a simple message: U = U. Researchers from all the major treatment as prevention studies have endorsed it. So has the Government of Canada.
What about other STIs?
Maintaining an undetectable viral load can prevent HIV but it does not prevent the transmission of other sexually transmitted infections (STIs), such as chlamydia, gonorrhea and syphilis. Condoms can reduce the risk of many STIs, so you might want to use HIV treatment and condoms. Also, as STIs can be symptom-free regular STI testing is recommended for all sexually active people a minimum of once per year.
How can I make U = U work for me?
Take your HIV treatment as prescribed and see your healthcare provider regularly. Your ongoing healthcare should include blood tests to check your viral load and ensure that it remains undetectable. Wait until you have had at least two consecutive undetectable viral load test results before depending on this strategy.
To make this strategy keep working for you taking your meds is key. If you have trouble taking them every day, don’t be afraid to ask for help from your doctor, pharmacist and/or counsellor.
If your viral load does not become undetectable or if it becomes detectable again, this can increase the risk of transmission. In that case, you may need to use other prevention strategies, such as condoms or PrEP (for your partner(s)) until your viral load becomes undetectable.
* Development of this U=U page and related ACNS U=U programming was supported by a Community Education and Services Grant from ViiV Healthcare.