Post-exposure prophylaxis (PEP) for HIV must be initiated as soon as possible, ideally within 2 hours, and preferably within 24 hours of exposure. However, the period during which PEP is most efficacious is often said to be within 72 hours of exposure. Most exposures have only a low risk of HIV t fileslib. Contact tracing and Post-exposure prophylaxis: WHO guidance Global consultation of NLP managers, partners and affected persons, 26-30 October 2020 Chemoprophylaxis with SDR: efficacy •Scenario 1: Leprosy among contacts who did not receive SDR •Periodic follow up of contacts and treatment with MDT of cases among them •Leprosy incidence reduces The goal of post-exposure prophylaxis (PEP) is to reduce the risk of transmission of HIV following accidental exposure to the virus. It is most efficacious if started within 72 hours of exposure. [3] [49] The recommended treatment duration is 28 days. [3] [4] [46] Treatment must be adhered to strictly, and timing must be observed to maximise the effect of PEP.