With worldwide clinical trials currently under way for a drug regimen that could boost HIV immunity before exposure—known as pre-exposure prophylaxis (PrEP)—public health officials worry that high-risk groups such as men who have sex with men (MSM) might abandon condoms and have unprotected sex if the pill becomes widely available, ABC News reports.

“The important thing to realize is that it's not just an evening-before pill that people pop,” said Albert Liu, MD, director of HIV prevention intervention studies at the San Francisco Department of Public Health.

While recent studies show that few MSM have tried using PreP instead of a condom—in a Boston study, only one respondent out of 227 admitted to doing so—experts fear that FDA approval of a PrEP regimen could boost infection rates.

“The problem with it is the idea of a disinhibitor,” said Sean Strub, founder of POZ Magazine, told ABC News. “I think of it more in terms of Gardasil and also, even birth control. Virtually every woman who becomes pregnant and did not want to be knows how to avoid it. It's applying that knowledge at the moment of sexual interaction that gets complicated.”