Professor Cooper is one of the most influential clinical scientists worldwide in the field of HIV/AIDS. Shortly after the Human Immunodeficiency Virus (HIV) was discovered in 1984, he published a seminal paper in the prestigious medical journal The Lancet, which described the initial encounter of HIV with the human immune system. He has been a key investigator in proving the efficacy of highly active antiretroviral therapy and implementing its benefits. He is one of the first clinical scientists to recognize the metabolic toxicities of antiretroviral therapy and to contribute to an understanding of the pathogenesis. Moreover, Professor Cooper has been instrumental in the international fight against HIV/AIDS in the developing world.