Polio-like paralysis can be caused by a number of enteroviruses, and there are cases in the United States every year. This is a large number of cases, but there

Polio-like paralysis can be caused by a number of enteroviruses, and there are cases in the United States every year. This is a large number of cases, but there's no reason to believe it has anything to do with polio or the vaccine (the U.S. does not use the attenuated vaccine that occasionally causes polio-like side effects). Rather, it's cause is likely a as yet unknown enterovirus.