Taking a drug to prevent an illness. Primary prophylaxis is the use of drugs to prevent a first occurrence of illness. Secondary prophylaxis is the use of drugs to prevent re-occurrence of illness. Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) for HIV are both forms of primary prophylaxis.
Learn more about HIV, including who’s at risk, where to get tested, and how you can prevent it.