The 1952 polio epidemic killed 3,145 and paralysed 21,269 men, women and children in the US.  Two years later, on 23 February 1954, Virologist Jonas Salk brought a glimmer of hope to Pittsburgh.  On this day,  61 years ago, the first large-scale inoculations of children began today. Just over a year later, the vaccine was declared by the University of Michigan to...