https://apnews.com/561a40f49436471f915e1a53e1424ffe > PITTSBURGH (AP) — Peter Salk still remembers the trepidation he felt when his father came home from work one day in May 1953 and promptly began boiling a set of needles and syringes on the kitchen stove. > With several years of research and promising results in monkeys fueling high hopes, Dr. Jonas Salk had brought from his lab at the University of Pittsburgh a still-experimental vaccine candidate to their Pine home. His family would become among the first humans in the world to test a shot against the mysterious polio virus crippling and killing children.