Bruce Walker is the Director of the Ragon Institute of MGH, MIT and Harvard, a Professor of Medicine at Harvard Medical School, and a Howard Hughes Medical Institute Investigator. In addition to his clinical duties as a board certified Infectious Disease specialist, his research focuses on cellular immune responses in chronic viral infections, with a particular focus on HIV. He leads an international translational clinical and basic science research effort to understand how some rare people who are infected with HIV, but have never been treated, can fight the virus with their immune system. Walker is also an Adjunct Professor at the Nelson Mandela School of Medicine in Durban, South Africa. There he collaborates with the Doris Duke Medical Research Institute at the University of KwaZulu-Natal and serves as a Principal Investigator in the HIV Pathogenesis Programme, an initiative to study the evolution of the HIV and the immune responses effective in controlling this virus, as well as to contribute to training African scientists. He is a member of the Steering Committee for the KwaZulu-Natal Research Institute for TB and HIV (K-RITH), a 10-year initiative funded by HHMI to build a state of the art TB-HIV research facility at the heart of these dual epidemics in South Africa. Walker is also a member of the American Academy of Arts and Sciences, American Society for Clinical Investigation (ASCI), the American Association of Physicians (AAP), and the Institute of Medicine (IOM) of the National Academy of Sciences.