When was the killed poliovirus vaccine developed by Dr. Jonas Salk?
This is a bit of a trick question. It depends on how one defines “developed.” Jonas’ work with poliovirus began in 1948, as part of a National Foundation for Infantile Paralysis program to identify all types (varieties) of poliovirus. The NFIP initiated the typing program because it was necessary to make sure all types of poliovirus were known in order to develop an effective vaccine of any kind. The typing project was completed in 1951, but before the completion of that study (in 1950 or 1951) Jonas’ lab began to work with the recently developed method of growing poliovirus in tissue culture (developed by Enders, Weller and Robbins at Harvard, for which they received the Nobel prize). As usual, after initial testing in vitro (i.e. in test tubes and bottles), studies with candidate vaccines were performed in animals (monkeys). The first administration of a candidate vaccine to humans occurred in June 1952, for safety testing and to evaluate the immunologic response to vaccination. The
