What exactly is PrEP?

PrEP stands for pre-exposure prophylaxis, and is a term that first gained widespread use in HIV prevention. Generally speaking, it means taking a medication daily to prevent an infection before exposure, though may be taken intermittently (instead of daily) in some situations for HIV prevention. In the DISCO study, STI PrEP means taking a doxycycline pill daily with the goal of preventing STIs.