Understanding HIV Viral Loads

What does U=U mean? The catchy shorthand, used in the context of the human immunodeficiency virus (HIV), stands for Undetectable = Untransmittable. The slogan refers to the idea that if an HIV-infected individual achieves and maintains an undetectable viral load—the virus is at such low levels that it is undetectable in their bloodstream—then they are unable to transmit HIV to their sexual partner.

In the past, an HIV-positive diagnosis came with, among other issues, the heavy burden of knowing that having sex could seriously affect your partner's health. But thanks to advances in modern medicine, HIV can become untransmittable if patients seek early treatment and use it consistently.

Individuals with HIV can achieve and maintain an undetectable viral load through the consistent use of a treatment called antiretroviral therapy (ART), according to medical experts.

The science behind U=U

More than a decade's worth of studies that examined data from more than 600 heterosexual couples using ART have validated the treatment's ability to prevent the sexual transmission of HIV when used consistently, according to the National Institute of Allergy and Infectious Diseases.

Additional large-scale research conducted on male-to-male couples has also confirmed these findings. In fact, one such body of research known as the PARTNER 2 Study tracked about 800 couples. One of the partners in each couple was HIV-positive and using ART. The study concluded, after documenting 77,000 condom-free acts, there was not a single case of HIV transmission among these couples.

Bringing the level of HIV detectability in your bloodstream down as much as possible can benefit both you and your partner. Even if you've achieved an undetectable viral load, however, it's a good idea for your partner to continue to take some extra precautions. Just because someone's viral load is undetectable does not mean their risk of transmission is zero. It's important that both partners stay on top of medication compliance and follow-up visits with medical specialists to make sure the medications are working well.

Partners of people with HIV should also talk to their doctors to evaluate the benefits of PrEP, a preventive strategy, for personal risk reduction.

Remaining diligent is particularly important because individuals who have maintained an undetectable viral load for an extended period of time may still experience an occasional spike of HIV levels in their blood. Also known as transient viremia, a sudden increase in viral load occurs in 10 percent of individuals who use ART consistently, according to researchers.

Don't underestimate the importance of consistently taking your medication. Studies have shown that skipping ART medication for as little as three to six days can cause your viral load to reach a sexually transmissible level. Doctors use many treatment algorithms and different antiviral combinations, particularly if a patient has side effects or other issues with a certain regimen. Many patients with HIV often have a specialist in infectious diseases monitoring and managing their treatment plans.

Key points to keep in mind

It's important to remember that U=U refers only to the sexual transmission of HIV. Anyone with HIV should aim to keep viral loads down for their individual benefit. However, doing so won't necessarily prevent the transmission of HIV from a pregnant mother to her baby. The same goes for individuals who are sharing needles.

U=U is evidence of the great headway being made in helping HIV patients and their partners reduce risk, improve quality of life and decrease anxiety. In order to maximize the benefits of U=U, strict compliance with medications and treatment plans is essential.

As of now, there is no definitive cure for HIV or the condition it can cause, AIDS (acquired immunodeficiency syndrome). And while achieving and maintaining an undetectable viral load doesn't mean the virus is gone, it does mean that you can have a safer sex life.