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Childhood Vaccinations

Polio Vaccine

Dr. Jonas Salk developed the first inactivated polio vaccine in 1955.
Dr. Jonas Salk developed the first inactivated polio vaccine in 1955.
©2006 Publications International, Ltd.

While there has not been a polio epidemic since the 1950s, it's important to have all the facts about polio and be sure to get your children immunized.

Polio Basics

Polio is caused by a virus that enters the body through the mouth, usually from hands contaminated with the stool of an infected person. Objects touched by contaminated hands, such as eating utensils, can also spread the virus. There are three types of poliovirus, so a person could possibly be infected three times.


In about 95 percent of cases, polio produces no symptoms at all (known as asymptomatic polio). In the 4 percent to 8 percent of cases in which there are symptoms (symptomatic polio), the illness appears in three forms:

  • Abortive polio is limited to flulike symptoms, such as upper respiratory infection, fever, sore throat, and a general feeling of illness.
  • Nonparalytic polio is a more serious form and produces symptoms of mild meningitis, such as sensitivity to light and neck stiffness.
  • Paralytic polio is a severe, debilitating form of the disease that occurs in about 1 to 2 percent of cases. It can result in partial or full paralysis of the breathing muscles and extremities, necessitating breathing support. In fact, the "iron lung" was developed for people with paralytic polio.

Who's at Risk for Polio

Polio is most common in infants and young children, but severe complications have occurred most often in adults. Although cases of polio are basically nonexistent in the United States today, the disease is still a big problem in some developing countries.

Defensive Measures Against Polio

There hasn't been a polio epidemic in the United States since the 1950s, but the need for protection from the virus remains. The two most effective ways to prevent polio are:

  • Cleanliness. Polio is transmitted primarily through ingesting items, directly or indirectly, that are contaminated with feces. Not all stools carry the virus, but it's a good idea to wash hands after using the bathroom, changing a diaper, or coming into contact with questionable materials.
  • Immunization. The inactivated polio vaccine (IPV) used today in the United States stimulates the immune system to produce antibodies that fight the polio virus if a person comes in contact with it. Dr. Jonas Salk developed the first IPV in 1955, and an enhanced-potency version came about in 1988. Other parts of the world use an oral polio vaccine (OPV) that was first developed by Dr. Albert Sabin in 1961. OPV is based on a live, but weakened, form of the virus. OPV is cheaper, doesn't have to be administered by healthcare professionals, and unlike IPV is effective in stopping outbreaks of the "wild" poliovirus (those outbreaks not related to the vaccine). However, it can, on rare occasions, cause paralysis.

In the United States, it's currently recommended that children have four doses of IPV between the ages of 2 months and 6 years. The Centers for Disease Control and Prevention and the American Academy of Pediatrics recommend three equally spaced doses of IPV be given before the age of 18 months, plus an IPV booster given between the ages of 4 and 6, when children are entering school.

If you're planning to travel outside the United States, particularly to countries where polio still exists, be sure that you and your family are up to date on complete polio vaccinations. Afghanistan, India, Nigeria, and Pakistan still have endemic polio circulating, and the virus could be introduced to other countries. If the polio virus were to occur in a country where not enough people have been immunized, it would spread like wildfire.

Shingles and chickenpox are caused by the same virus, and in fact, a dormant varicella-zoster virus can later become shingles. Read the next section for information about the shingles vaccine.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.