Maurice Hilleman's mother died a day after he was born and his twin sister stillborn. As an adult, he said that he felt he had escaped an appointment with death. He made it his life's work to see that others could do the same. Born into the life of a Montana chicken farmer, Hilleman ran off to the University of Chicago to become a microbiologist, and eventually joined Merck, the pharmaceutical company, to pursue his goal of eliminating childhood disease. Chief among his accomplishments are nine vaccines that practically every child gets, rendering formerly dread diseases—including often devastating ones such as mumps and rubella—practically toothless and nearly forgotten; his measles vaccine alone saves several million lives every year.