Until 1991, Dr. Plotkin was Professor of Pediatrics and Microbiology at the University of Pennsylvania, Professor of Virology at the Wistar Institute and at the same time, Director of Infectious Diseases and Senior Physician at the Children’s Hospital of Philadelphia. In 1991, Dr. Plotkin joined the vaccine manufacturer, Pasteur-Mérieux-Connaught (now Sanofi Pasteur), where for seven years he was Medical and Scientific Director. He developed the rubella vaccine now in standard use throughout the world, is co-developer of the newly licensed pentavalent rotavirus vaccine, and has worked extensively on the development and application of other vaccines including anthrax, oral polio, rabies, varicella, and cytomegalovirus. Dr. Plotkin is a key opinion leader in the development of vaccines and has received numerous awards and honors, including named lectures in his honor.