What is Polio?

Polio is an infectious disease caused by a virus that lives in the throat and intestinal tract. It is most often spread through person-to-person contact with the stool of an infected person and may also be spread through oral/nasal secretions. Polio used to be very common in the U.S. and caused severe illness in thousands of people each year before polio vaccine was introduced in 1955. Most people infected with the polio virus have no symptoms, however for the less than 1% who develop paralysis it may result in permanent disability and even death.