photograph by Harold Low, "Gift. Dr. Heidelberger." · Public domain

Often called the father of modern immunology, he showed alongside Oswald Avery that the polysaccharides coating pneumococcus bacteria act as antigens, work that helped establish that antibodies are proteins — a founding insight of the field. His long career at Columbia and later NYU was recognized with the National Medal of Science in 1967 and two Lasker Awards for basic medical research, in 1953 and again in 1978, twenty-five years apart.