Pharmaceutical company Gilead Sciences announced Wednesday the Food and Drug Administration (FDA) has approved its six-month, twice-yearly HIV PrEP injection, which was found in trials to be more than 99.9 percent effective among participants.

Gilead’s product Yeztugo, a form of lenacapavir, was approved for reducing the risk of sexually acquired HIV in adults and adolescents when injected twice a year. Lenacapavir is also marketed as Sunlenca, administered orally or through injection, as a treatment for HIV/AIDS in combination with other drugs. The drug is solely manufactured by Gilead.

There are currently three available HIV PrEP options: two oral pills taken daily — Truvada and Descovy — and a long-acting injection called Apretude administered every two months.

“Yeztugo could be the transformative PrEP option we’ve been waiting for — offering the potential to boost PrEP uptake and persistence and adding a powerful new tool in our mission to end the HIV epidemic,” Carlos del Rio, co-Director of the Emory Center for AIDS Research, said in a statement shared by Gilead.

In a Phase 3, double-blind, randomized study, there were only two HIV infections among 2,179 participants who received Yeztugo subcutaneous injections twice a year.

Lenacapavir is currently not approved for HIV prevention outside of the U.S., though it is approved for treating HIV in several countries.

“In the U.S., Gilead is working closely with insurers, healthcare systems and other payers with the goal of ensuring broad insurance coverage for Yeztugo,” the company said in a statement. “Additionally, for eligible commercially insured individuals with commercial insurance, Gilead’s Advancing Access® Co-Pay Savings Program will reduce out-of-pocket costs to as little as zero dollars.”

Carl Schmid, Executive Director of the HIV+Hepatitis Policy Institute, called the approval a “monumental advance in HIV prevention.”

“Long-acting PrEP is now not only effective for up to six months but also improves adherence and will reduce HIV infections—if people are aware of it and payers, including private insurers, cover it without cost-sharing as a preventive service,” said Shmid.

“Recent actions by the Trump administration to decimate HIV prevention jeopardize access to preventive measures such as PrEP,” he added.

“In fact, the president’s budget zeroes out all CDC HIV prevention and surveillance funding, hampering our nation’s ability to make people aware of and access new HIV prevention measures. Dismantling these programs means that there will be a weakened public health infrastructure and much less HIV testing, which is needed before a person can take PrEP.”

The Hill has reached out to the White House for comment.