The Centers for Disease Control has finally admitted what activists and medical experts have been saying for years: People whose HIV loads are undetectable can't transmit the virus.

It might seem like a given, but as HIV Plus reports, its the first time the august body has made the claim.

In a memo released Wednesday, National Gay Men’s HIV/AIDS Awareness Day, the CDC stated that "when [antiretroviral treatment] results in viral suppression, defined as less than 200 copies/ml or undetectable levels, it prevents sexual HIV transmission."

"Across three different studies, including thousands of couples and many thousand acts of sex without a condom or pre-exposure prophylaxis (PrEP)," it continues, "no HIV transmissions to an HIV-negative partner were observed when the HIV-positive person was virally suppressed. This means that people who take ART daily as prescribed and achieve and maintain an undetectable viral load have effectively no risk of sexually transmitting the virus to an HIV-negative partner."

Nearly half of all people with HIV in the U.S. are undetectable, thanks to receiving proper treatment with anti-viral medication.

Bruce Richman, executive director of UequalsU.org and the Prevention Access Campaign, tells HIVPlus the statement can't be overestimated. "The CDC’s new and unequivocal language is a result of [the U.S. Department of Health and Human Services’] unprecedented review of transmission risk messaging across departments which will be rolling out core messaging in the coming weeks and months."

On a less upbeat note, the memo also pointed out that gay and bisexual men are disproportionately affected by the virus, with more than 26,000 being diagnosed with HIV in 2015 alone. That's two-thirds of all new cases in the U.S.

And Republican threats to the Affordable Care Act; Planned Parenthood; and funding for HIV awareness, treatment and education make our gains even more precarious.

"If Congress repeals the ACA without simultaneously replacing it with programs that ensure comprehensive health coverage for the same if not more individuals... people with HIV and others would lose access to the care and treatment that they rely on to remain healthy," says Carl Schmid of the AIDS Institute. "People with HIV, who depend on a daily drug regimen, cannot risk losing access to their health coverage, not even for a single day."