George Rainer Siber (born September 7, 1944) is an internationally recognized medical researcher and vaccine expert with 40 years of experience in developing numerous vaccines, therapeutic antibodies, and diagnostic agents for infectious diseases.Siber is a former Harvard professor, current Adjunct Professor at Johns Hopkins University and Professor at the University of Massachusetts Medical School, former Executive Vice President and Chief Science Officer of Wyeth (developer of Prevnar, Meningitec, Rotashield, and FluMist), and Advisory Committee member of the World Health Organization, US National Institutes of Health, Gates Foundation, and the National Institute of Allergy and Infectious Diseases.