Maurice Ralph Hilleman (August 30, 1919 – April 11, 2005) was an American microbiologist who specialized in vaccinology and developed over 40 vaccines, an unparalleled record of productivity. Of the 14 vaccines routinely recommended in current vaccine schedules, he developed eight: those for measles, mumps, hepatitis A, hepatitis B, chickenpox, meningitis, pneumonia and Haemophilus influenzae bacteria. He also played a role in the discovery of the cold-producing adenoviruses, the hepatitis viruses, and the potentially cancer-causing virus SV40.
He is credited with saving more lives than any other medical scientist of the 20th century. Robert Gallo described him as "the most successful vaccinologist in history".
"Yet almost no one knew about him, saw him on television, or read about him in newspapers or magazines. His anonymity, in comparison with Madonna, Michael Jackson, Jose Canseco, or an assortment of grade B actors, tells something about our society's and media's concepts of celebrity; much less of the heroic."