U=U Frequently Asked Questions

In September 2017, the New York State Department of Health became the first state health department in the Unites States to sign on to the Prevention Access Campaign’s Undetectable equals Untransmittable (U=U) Consensus Statement. In doing so, the Health Department endorsed the following statement:

"People living with HIV on ART with an undetectable viral load in their blood have a negligible risk of sexual transmission of HIV. Depending on the drugs employed it may take as long as six months for the viral load to become undetectable. Continued and reliable HIV suppression requires selection of appropriate agents and excellent adherence to treatment. HIV viral suppression should be monitored to assure both personal health and public health benefits."

The framework of U=U offers a unique opportunity to dismantle HIV stigma and discrimination, and reemphasizes the critical importance of antiretroviral therapy (ART), daily adherence, and continuous engagement in medical care for people living with HIV.

**NOTE: Definitions are available via mouse hover on italicized words below.

1. What does "undetectable" mean?

The word "undetectable" is the lowest limit of the laboratory tests (lab tests) used to measure HIV viral load. Some viral load tests are very sensitive and can find – or detect – HIV in a sample of blood when there are only 20 copies of the virus per milliliter (mL). Other viral load tests need up to 200 copies per mL of blood to detect any HIV. In the context of U=U, it does not matter which type of test your doctor uses to measure your viral load. As long as your viral load remains below 200 copies/mL, your risk of sexually transmitting HIV is negligible.

2. What does "untransmittable" mean?

If your viral load is undetectable you will not sexually transmit HIV, making your HIV "untransmittable". In other words, HIV will not be passed sexually to another person through saliva, pre-seminal fluids , semen , rectal fluids or vaginal fluids . (As the scientific evidence currently stands, U=U applies only to sexual transmission.)

3. What does negligible risk mean?

Negligible risk means so small or unimportant as to be not worth considering; insignificant, having effectively no risk of sexually transmitting the virus. For U=U, "risk" is a projection – talking about chances of something happening in the future – and cannot be quantified, or given an exact number. What can be said for sure is that there have been zero transmissions in studies so far. And those studies included tens of thousands of unprotected sex acts. Undetectable individuals do not transmit HIV sexually, so the risk of transmission is negligible.

4. Are U=U and Treatment as Prevention (TasP) the same?

U=U and TasP are one and the same, just different ways of stating the same concept about people living with HIV (PLWH) who are on effective ART. TasP has been used widely in medical and public health literature for years and means what it sounds like: taking ART and staying virally suppressed stops people from transmitting HIV, meaning it also acts as a form of HIV prevention. Both TasP and U=U are based on the important goal of having everyone with HIV be aware of their status so they can take ART. ART not only improves the health of PLWH, but also reduces the virus in a person’s cells to the point of being "undetectable". Viral load measures the effectiveness of ART. When a person is undetectable, they do not transmit HIV sexually. U=U has been taken up by the broader HIV-affected community to spread awareness that if you are undetectable, you will not transmit HIV. U=U sends a hopeful, empowering message and addresses the stigma often associated with living with HIV and an HIV/AIDS diagnosis.

5. How does U=U address stigma?

Since the beginning of the HIV epidemic, PLWH have been seen by many as "infectious", feeding widespread discrimination and the unfortunate internalization of shame and stigma . HIV-negative people feared starting relationships with people living with HIV, and sex with a person living with HIV was seen as a possible health risk to the HIV-negative partner. U=U presents an opportunity to silence those damaging narratives by breaking the link between sex and HIV transmission.

6. Does U=U apply to all types of sex?

Yes. PLWH with an undetectable viral load do not transmit HIV through insertive or receptive anal sex, vaginal sex, or oral sex.

7. How do we know that U=U? What is the evidence?

The evidence for U=U comes from several groundbreaking research studies and clinical trials. A study called HPTN 052, a randomized control trial to find out if ART can stop transmission of HIV in sero-different couples, enrolled more than 1,700 sero-different heterosexual couples who were randomly assigned to have the HIV-positive partner either immediately start ART or delay the start of ART. Over time, results among study participants showed no linked transmissions when the index (HIV+) partner was suppressed.

Another study, the PARTNER Study, which was carried out at 13 sites in Europe, had specific enrollment eligibility criteria that included undetectable sero-different couples (both heterosexual and men who have sex with men) who had condom-less sex. In what were a reported 58,213 sexual encounters during this study, there were no transmissions linked to the HIV-positive partners. In the summer of 2017, at the International AIDS Conference in Paris, the results of the Opposites Attract study were reported. It studied 358 gay male sero-different couples and found no linked HIV transmissions in nearly 17,000 condom-less sexual acts.4

The findings from these three key studies show that not only does being on effective antiretroviral treatment improve the health of each person with HIV, it also keeps them from transmitting HIV to sexual partners.

8. Suppressed Viral Load and "Undetectable"—is there a distinction? Is there a difference in transmission risk with a viral load of 200 copies/mL vs. 20 copies/mL?

When it comes to transmission risk, there is no difference between suppressed viral load and undetectable viral load. As long as your viral load is below 200 copies/mL, and has stayed that way for at least six months, your risk of sexually transmitting HIV remains negligible.  

The word "undetectable" comes from the sensitivity of the laboratory viral load assay used. Even if the viral load test could not detect virus in the blood sample, it does not mean HIV has disappeared from the body, but that ART has suppressed the virus so much that the usual lab tests cannot "detect" or find it.

"Undetectable" is now commonly defined as having fewer than 20 copies/mL because a lot of lab tests can now "detect" HIV at that level. And " viral load suppression" is usually defined as having fewer than 200 copies of HIV per milliliter of blood (copies/mL). However, in the context of U=U, the two terms can be used interchangeably: a person is considered undetectable (and therefore untransmittable) if they have reached viral load suppression of fewer than 200 copies/mL.

9. How long do I need to be on ART and be ‘undetectable’ in order not to transmit HIV?

First, being on ART and being undetectable are two different things. When you start on ART, it takes a while for the medication to do its job. Generally, if the ART is working, it should reduce the amount of virus in your blood to an undetectable level within a few months. Once you are undetectable (under 200 copies/mL ), you then need to stay undetectable for at least six months before your HIV is considered "untransmittable." In other words, you need at least two confirmatory tests that your viral load is less than 200 copies/mL - at the beginning and the end of a six-month period - before you can use your undetectable status as a method of HIV prevention.

10. If I am undetectable and there is a "blip" in my viral load, am I still untransmittable?

Yes, you are still untransmittable. Sometimes, even when you take your medication every day, the HIV viral load test notes that it can "see" or "detect" virus in your blood. This is commonly known as a viral "blip". Depending on the laboratory, a "blip" is usually between 16 and 199 copies in some viral load tests. In other viral load tests this "blip" would not have even been found or detected, which would still be in the negligible risk range. These 16 to 199 copy viral "blips" have not been shown to increase the transmission of HIV, but the viral load test should always be repeated because sometimes it is an early sign that the ART medication is losing its power to suppress the virus. Most of the time, though, viral load goes back to undetectable levels without any changes in treatment.

11. How often should I have my viral load checked?

A key part of U=U is remaining engaged in ongoing medical care. If you are using your undetectable status as an HIV prevention method,, it is advisable that you check with your doctor and consider having your viral load tested with the frequency they recommend. No matter what your HIV status is, your sexual health is important and deserves regular attention. If your partner is on pre-exposure prophylaxis (PrEP), consider scheduling your quarterly medical visits at similar times. If either of you has other sexual partners, these quarterly visits are a good chance to get checked for sexually transmitted infections (STIs) and keep up to date with your other health screenings.

12. If I am HIV negative and my HIV-positive sexual partner is undetectable, do we still need to use condoms or PrEP?

In the age of U=U, prevention and safer sex now means an undetectable viral load, condoms, PrEP, or a combination of these, depending on your needs and feelings. If your partner is undetectable, they cannot transmit HIV through sex. However, your decisions about condoms should be based on your sexual behavior and your partner(s)’ sexual behavior. Remember that U=U only protects against HIV transmission! Condoms are still the best way to prevent STIs and pregnancy. If you are HIV negative and have other partners, you should consider (PrEP) and condoms or emergency PEP (post-exposure prophylaxis). However, if you are in a monogamous relationship (neither one of you is having sex with other people) and your partner is undetectable, you could choose not to use any other forms of protection. It is very important to have an open and honest conversation with your sexual partner(s) and your doctor about which prevention methods are right and most comfortable for you.

13. How is PEP different from PrEP?

PrEP and PEP are both forms of HIV prevention for people who are HIV-negative. A big difference between PrEP and PEP is that PrEP is taken before potential exposure, while PEP is taken after possible exposure to HIV. While PEPis prescribed in emergency situations and should be taken within 36 hours of exposure, PrEP is a daily pill that people can take to protect themselves against HIV if they think they will be sexually exposed.  

14. I am HIV negative. My partner has been undetectable for over 6 months, and now we want to have a baby. Why does our doctor say I should take PrEP?

The research on HIV transmission risk in couples trying to conceive (get pregnant) when the HIV-positive partner is durably virally suppressed is still limited. If you are HIV negative and are trying to get pregnant with an HIV-positive partner's sperm, it is generally recommended that you be on PrEP, regardless of your partner's viral load. This is, however, a clinical judgment and a decision you and your doctor(s) should make considering what is best for you, your partner, and your future child.

15. I am HIV negative. My partner was recently diagnosed with HIV and has just started antiretroviral therapy (ART). How does U=U apply to us?  

It is great that your partner has started ART, but until they have been undetectable for 6 months you should consider PrEP and/or condoms for prevention.

16. What if I am undetectable and I use injection drugs?

If you are undetectable and use injection drugs, your chances of sexually transmitting HIV are negligible. However, even with an undetectable viral load, anyone who injects drugs should always use clean/new equipment and never share works. U=U does not apply at all to HIV transmission with shared works. While stigma as well as inadequate and intermittent health care remain challenges for many people with a history of injection drug use who are living with HIV, it is still important for them to remain engaged in medical care to become virally suppressed.

17. What if I am undetectable and I want to breastfeed?

At this time, U=U does not apply to HIV transmission during breastfeeding. While the risk of mother-to-child transmission of HIV is significantly reduced with the effective use of ART and an undetectable viral load, neither infant antiretroviral prophylaxis nor fully suppressive maternal ART eliminate the risk of HIV transmission through breastmilk. It is, therefore, recommended that women in the United States who are living with HIV refrain from breastfeeding and feeding their expressed breastmilk to their infants .

18. What does U=U mean for people living with HIV who are not "undetectable"?

Everyone with HIV in New York State should get into treatment and get the services they need to be as healthy as possible. Being adherent to ART reduces transmission risk and comes with many important health benefits. It is important to understand that many people living with HIV may not be in a position to reach undetectable viral load status due to factors that are beyond their control. These reasons may include problems accessing treatment, past ART treatment that led their HIV virus to develop resistance or cause toxicities, and other comorbidities.