In the span of four months, at least 94 children in 33 U.S. states have developed a devastating form of paralysis with symptoms similar to polio. Some require a ventilator to breathe. And some of the greatest government health minds in the country say they have no idea what’s causing it. At the same time, during the past four months, at least 12 children have died after falling ill with a respiratory virus called Enterovirus D-68 (EV-D68). Again, federal health officials are at a loss to explain the origin of the epidemic. Are the mysterious outbreaks linked? The Centers for...