In the 1960s, he played a pivotal role in discovery of a vaccine against rubella virus while working at Wistar Institute in Philadelphia. Plotkin was a member of Wistar’s active research faculty from 1960 to 1991. Today, in addition to his emeritus appointment at Wistar, he is emeritus professor of Pediatrics at the University of Pennsylvania. His book, "Vaccines",[1][2] is the standard reference on the subject.[3][4] He is an editor with Clinical and Vaccine Immunology, which is published by the American Society for Microbiology in Washington, D.C..