EXPLAINER: What to know about polio spreading in New York

The polio virus has been found in New York sewage, but officials are stressing that the highest risk is for people who haven’t been vaccinated. U.S. children are still routinely vaccinated against polio and the shots are considered to be highly effective. According to the Centers for Disease Control and Prevention, about 93% of 2-year-olds had received at least three doses. And adults who were fully vaccinated as kids continue to have protective antibodies in their blood for decades. Most people who catch polio have no visible symptoms, but a rare few can be paralyzed by it. People who are unvaccinated or incompletely vaccinated are at greatest risk of that paralysis.