With polio's return, here's what back-to-schoolers need to know

Before polio vaccines became available in the 1950s, people wary of the disabling disease were afraid to allow their children outside, let alone go to school. As polio appears again decades after it was considered eliminated in the U.S., Americans unfamiliar with the dread disease need a primer on protecting themselves and their young children — many of whom are emerging from the trauma of the COVID-19 pandemic.

Polio is short for "poliomyelitis," a neurological disease caused by a poliovirus infection. Of the three types of wild poliovirus — serotypes 1, 2, and 3 — serotype 1 is the most virulent and the most likely to cause paralysis.