Undetectable Equals Untransmittable: Can You Get HIV from Someone Who Is Undetectable?

Human immunodeficiency virus (HIV) causes a lifelong infection that can lead to serious damage to the immune system over time. HIV was once an untreatable illness that caused serious health problems and death. 

But today, thanks to modern antiretroviral therapy (ART), people with an HIV infection can live long and healthy lives. And, not only that, modern ART therapy can help people reach an undetectable viral load. 

People with an undetectable viral load can’t pass the HIV virus to other people through sex. Experts have created the U=U campaign — which stands for “undetectable equals untransmittable” — to help people understand what it means to live with undetectable HIV. Here’s what you should know if you’re living with undetectable HIV or having sex with someone who has undetectable HIV. 

What is undetectable HIV?

Undetectable HIV, or an undetectable viral load, is a medical term that describes a situation where a person has fewer than 200 copies of the HIV virus per milliliter of blood. 

That means when people with an undetectable viral load take an HIV blood test, they get a negative result. The levels of virus in their body (and blood) are so low that tests can’t find the virus. In other words, they get the same test results as a person who doesn’t have an HIV infection. 

But having an undetectable viral load doesn’t mean you’re “cured.” You have to keep taking ART as prescribed to keep an undetectable viral load. If you stop taking your medications, the HIV virus starts to grow in your body again. The virus will show back up in blood tests and start damaging the immune system and causing other health problems.

How do you get an undetectable viral load?

You can reach an undetectable viral load by taking ART as prescribed by your healthcare team. You have to take all your medications consistently without skipping or missing doses. 

Most people reach an undetectable viral load after taking ART for 7 to 12 months. 

When you first start ART treatment, the medication lowers how much virus lives in your body (viral load). Within 1 to 5 months, the medication is able to lower your viral load so much that it’s no longer found on blood tests. You then need to maintain that undetectable viral load for 6 months. Once that happens, you have what’s known as “durably undetectable HIV.” At this point, you can no longer pass HIV to others through sex. You also won’t experience damage to your immune system. 

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What are the symptoms of undetectable HIV?

People with durably undetectable HIV don’t experience any HIV-related symptoms. Their immune system functions normally. That means they won’t develop the types of illnesses that once caused serious harm and even death in people living with HIV. 

Many experts believe people can maintain a durably undetectable HIV status for the rest of their lives, as long as they keep taking their medications as prescribed. 

Modern ART hasn’t been around long enough for experts to know this for sure. But, over time, this information will become available. 

So far, one study showed that 97% of people were able to maintain their undetectable status for 10 years. Experts expect that people with undetectable viral loads will have a normal life expectancy. 

Can you get HIV from someone who has undetectable HIV?

The HIV virus can pass from person to person through different ways. The risk of getting HIV depends on how you come in contact with the virus.

Having sex

You can’t get an HIV infection by having unprotected (without a condom) oral, anal, or vaginal sex with someone who has undetectable HIV. This is true for both same-sex and opposite-sex couples.

Several well-designed and highly regarded research studies have proven that the risk of passing the HIV through sex is essentially zero once someone reaches durably undetectable status. These studies include the PARTNER 1 and PARTNER 2 studies, as well as the Opposites Attract study.

Remember, U=U only when someone has a durably undetectable viral load. It’s important to use a condom or other barrier method until you or your partner have reached this milestone. 

Pregnancy

People who have a durably undetectable viral load during pregnancy are unlikely to pass HIV to their baby, as long as they take ART during pregnancy and for 2 to 6 weeks after birth. Research shows the risk of transmitting HIV is less than 1% when pregnant people take ART therapy as prescribed.

Needle sharing

It’s not clear if someone with an undetectable viral load can transmit HIV through needle sharing. To lower the chances of transmitting HIV, experts advise using clean equipment and not share needles or syringes.

Blood transfusions

People with an undetectable viral load can’t donate blood. Experts believe there’s still a risk for transmitting HIV to others through blood donation. That’s because the exposure to the virus is much greater during a blood transfusion than during sex. 

How do you maintain an undetectable HIV viral load?

You can maintain an undetectable HIV viral load by:

• Taking your ART as prescribed 

• Getting regular HIV tests to confirm that your viral load is undetectable

Even a brief interruption in your HIV treatment can cause your viral load to rise again. This means that you lose your durably undetectable status. You’ll need to start over again before you can once again be considered undetectable. 

It’s important to start ART as soon as you find out you have an HIV infection. People who start within 6 months of their diagnosis are less likely to have a sharp rise in their viral load if they have interruptions in their antiretroviral therapy. That means you’re more likely to quickly achieve an undetectable load once you restart therapy. This will protect your overall health. 

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Written by:

Brian Clista, MD

Dr. Clista is a board-certified pediatrician who works in private practice in Pittsburgh, Pennsylvania. He previously served as a National Health Service Corporation Scholar in the inner city of Pittsburgh for 11 years.

Edited by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

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