when was the polio vaccine introduced
Polio used to be very common in the United States 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.here are two types of vaccine that protect against polio: inactivated poliovirus vaccine (IPV) and oral poliovirus vaccine (OPV). IPV is given as an injection in the leg or arm, depending on the patient's age. Polio vaccine may be given at the same time as other vaccines.