Human Immunodeficiency Virus (HIV) attacks specific cells of the immune system, weakening the body’s ability to fight infections and disease. If left untreated, the immune system can become severely damaged, often leading to the development of acquired immune deficiency syndrome (AIDS). In 2014, an estimated 103,700 people were living with HIV in the United Kingdom. However, at present, there is currently no vaccine for HIV, with anti-retroviral drugs used in many countries both to prevent and treat the virus. In the United Kingdom, a course of drugs—known as post-exposure prophylaxis (PEP)—is given to individuals who have already tested positive for the virus, whilst preventative treatment—known as pre-exposure prophylaxis (PrEP)—for individuals at-risk of contracting the virus, is not currently provided to patients outside of a clinical trials environment.