1957 dummy.
Posted on: December 16, 2021 at 23:59:28 CT
TigerMatt MISS
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"By 1957, following mass immunizations promoted by the March of Dimes, the annual number of polio cases in the United States was reduced, from a peak of nearly 58,000 cases, to 5,600 cases. Eight years after Salk's success, Albert Sabin developed an oral polio vaccine (OPV) using live but weakened (attenuated) virus."