From the book:
Oshinsky reveals that polio was never the raging epidemic portrayed by the media, but in truth a relatively uncommon disease. But the specter of polio, like the specter of the atomic bomb, soon became a cloud of terror over daily life.
The Salk vaccine trials were the largest public-health experiment in American history, involving more than a million school children. Both a gripping scientific suspense story and a provocative social and cultural history, Polio opens a fresh window onto postwar America.