About a third of state health department websites do not provide any information about Undetectable Equals Untransmittable (U=U), according to research from George Washington University covered by aidsmap.com.

U=U refers to the fact that people living with HIV who take antiretrovirals and maintain an undetectable viral load don’t transmit HIV to others through sex; this is also referred to as treatment as prevention, or TasP. It’s important to note as well that folks with HIV who have a suppressed viral load also experience slower disease progression, enjoy better overall health and are less likely to develop opportunistic illnesses.

Publishing their findings in AIDS Patient Care and STDs, George Washington University researchers analyzed HIV prevention information offered on public health department websites for all 50 states. They found that 18 do not mention U=U by name. However, almost all websites provided information on pre-exposure prophylaxis (PrEP) to prevent HIV. PrEP is available as daily pills and long-acting injectables to prevent HIV.

“State health department websites serve as a free and trusted resource for health professionals and community members to access health information,” researchers wrote.

Researchers found that although 33 websites do mention U=U, many have gaps in information. Nine other websites offer links to external websites that cover U=U. PrEP and post-exposure prophylaxis (PEP) were covered in 46 and 42 state websites, respectively.

For the analysis, researchers gauged the accuracy of U=U information on whether the information explicitly stated: (1) that U=U means there is zero risk of transmission; (2) that U=U applies to sexual transmission specifically, meaning that it could not be misinterpreted as applying to injection or other risks; (3)  that U=U pertains to a person whose viral load is undetectable, or suppressed; and (4) that viral suppression needs to be sustained across time.

The researchers found that:

  • 27 states indicated zero transmission risk;
  • 29 states said this applied to sexual transmission specifically;
  • 30 states referred to a person whose viral load was undetectable, or suppressed;
  • 24 states mentioned that viral suppression needed to be sustained across time—for example, for at least six months, “durably” suppressed, etc..

When reviewing for the four criteria cited above, researchers found that only 18 websites contained accurate information on U=U. What’s more, 17 state websites used misleading or ambiguous language, such as “virtually no risk,” “minimal risk” or “effectively no risk.”

To learn more, click #U=U or read POZ’s HIV Basics on U=U. It reads in part:

Antiretroviral medications (ARVs) are primarily used to improve the health and well-being of people living with HIV. The U.S. Department of Health and Human Services recommends treatment for all people living with HIV, regardless of their CD4 cell count.


But effective treatment has an additional benefit: preventing HIV transmission of HIV. Studies have shown that HIV-positive people who maintain an undetectable viral load do not transmit the virus via sex, a fact known as Undetectable Equals Untransmittable, or U=U. In this case, undetectable is defined as less than 200 copies/milliliter.


In 2011, the HIV Prevention Trials Network 052 (HPTN 052) trial demonstrated that the use of ARVs by HIV-positive heterosexual men and women cut the odds that their HIV-negative partner would acquire the virus by 96%. The final study results, announced in 2015, showed that no participant with a fully suppressed viral load transmitted the virus to their long-term HIV-negative partner.


In 2014, interim analysis of the PARTNER trial—which focused on heterosexual and gay mixed-HIV-status couples in which the HIV-positive partner was taking ARVs—found that there were no transmissions between partners when the HIV-positive person had an undetectable viral load.


In 2017, the Opposites Attract study, which included gay male couples in which one partner had HIV and the other did not, found that there were zero cases of transmission of the virus in 16,889 acts of condomless anal sex. In 2018, the PARTNER 2 trial, which also enrolled mixed-status gay couples, offered further evidence.


These findings led the Centers for Disease Control and Prevention to conclude, “Across three different studies, including thousands of couples and many thousand acts of sex without a condom or pre-exposure prophylaxis (PrEP), no HIV transmissions to an HIV-negative partner were observed when the HIV-positive person was virally suppressed.”