Marrice Ralph Hilleman, an American microbiologist, developed over 40 vaccines, eight of which are currently used in dozens of countries. These are vaccines against measles, mumps (a vaccine developed by Hilleman with material from his daughter Jeryl Lynn, who had contracted mumps), hepatitis A and B, chickenpox, meningitis, pneumonia, and Haemophilus influenzae. He contributed to saving 129 million lives. (Estimate updated at the beginning of the 21st century.)
