Sir Gustav Nossal AC CBE (b. 1931) is an immunologist and medical scientist. Born in Austria, he emigrated with his family to Sydney in 1939. After studying in Sydney and Melbourne, he began his medical career in 1955. Ten years later he became director of the Walter and Eliza Hall Institute of Medical Research. Under his leadership until 1996 the Institute broadened its research activities to include cancer, multiple sclerosis, malaria and organ transplants. During much of this period Nossal was also Professor of Medical Biology at the University of Melbourne, and from 1994 to 1998 he was Chairman of the Australian Academy of Science. Since 1990 he has been chairman of the group of experts advising the World Health Organisation on its global programme of vaccines and immunisation. Nossal has been honoured with a great number of international awards and was Australian of the Year in 2000.