According to federal health officials, one-third of primary care doctors and nurses in the U.S. are unaware of Truvada.

Truvada is the once-daily pill that the Centers for Disease Control and Prevention (CDC) says offers 90 percent protection to gay men at risk of acquiring HIV from sex when taken as prescribed.

Truvada is the brand name for the treatment known as pre-exposure prophylaxis, or PrEP. It is currently the only such drug approved by the Food and Drug Administration for PrEP.

“Providers play a central role in increasing awareness and uptake of PrEP,” Dr. Eugene McCray, director of the CDC's division of HIV prevention, is quoted as saying by The New York Times.

The findings were released last week, ahead of World AIDS Day, which takes place Tuesday, December 1.