The U.S. Air Force has approved the use of a medication designed to prevent HIV infection for pilots and aircrew, overriding an older policy that prohibited its use. The pre-exposure prophylaxis treatment (PrEP) medication, commonly known as Truvada, helps reduce the risk of contracting the human immunodeficiency virus. Pilots and aircrew who wish to use PrEP must apply for a waiver. Read more about the drug and the waiver process in this Military.com story.