Children were especially vulnerable, so parents watched anxiously for any sign of infection, often keeping them away from swimming pools, movie theaters, bowling alleys, anywhere where there were crowds and the dreaded microbe might lurk. Travel and business were sometimes curtailed between places with outbreaks, and public health authorities imposed quarantines on healthy people who may have been exposed, in order to halt the spread of the disease. In the first half of the 1950s, with no cure and no vaccine, more than 200,000 Americans were disabled by the poliovirus. The virus was second only to the atomic bomb as to what Americans feared most.

Then, on April 12, 1955, public health officials at the University of Michigan announced that a “safe, effective, and potent” vaccine had been found. This set off a national celebration that recalled the end of World War II. Church bells rang, car horns honked, people wept with relief. President Eisenhower invited the vaccine’s inventor, Jonas Salk, to the White House. In a Rose Garden ceremony, the former Supreme Allied Commander told the scientist in a trembling voice, “I should like to say to you that when I think of the countless thousands of American parents and grandparents who are hereafter to be spared the agonizing fears of the annual epidemic of poliomyelitis, when I think of all the agony that these people will be spared seeing their loved ones suffering in bed, I must say to you I have no words in which adequately to express the thanks of myself and all the people I know—all 164 million Americans, to say nothing of all the people in the world that will profit from your discovery.”