This project would suit someone with a STEM background wanting to apply their talents to one of the most current challenges in global health. Since its introduction in 2012, pre-exposure prophylaxis (PrEP) has profoundly impacted efforts to eliminate HIV. This PhD programme will establish a deep understanding of HIV transmission in diverse populations where the use of PrEP is influenced heavily by social and behavioural factors. The student will develop mathematical models to explore the interaction between risk perception, PrEP adherence, and HIV transmission, focussing on the newly introduced long-acting PrEP and providing policy recommendations on HIV control.