<s>[INST] What is post-exposure preventive treatment? [/INST] Post-exposure preventive (PEP) treatment consists of medication, laboratory tests and counselling. PEP treatment must be initiated within hours of possible HIV exposure and must continue for a period of approximately four weeks. Research studies suggest that, if the medication is initiated quickly after possible HIV exposure (ideally within two hours and not later than 72 hours following such exposure), it is beneficial in preventing HIV infection. Source: UNAIDS. Link: https://www.unaids.org/en/frequently-asked-questions-about-hiv-and-aids. Field: Infectious Disease. Disease: HIV </s>