Polio (Poliomyelitis)

Polio Overview

What is Polio?

Polio is a highly infectious disease caused by the poliovirus. 

Most people infected with poliovirus have no symptoms. In some, polio can cause weakness and paralysis of the arms, legs, and breathing muscles and can result in permanent disability and even death.

Polio is most commonly transmitted from an infected person’s poop (feces). You can get polio if you put something in your mouth (food, objects, hands) that has infected poop on or in it.  The virus can be on an object even if it looks clean. Babies and toddlers are most likely to spread polio to others. People can spread polio up to two weeks before they show symptoms.

The virus can also be spread when person who has polio sneezes or coughs, and droplets get into another person's mouth or nose. 

Learn more about polio and how it affects people on the Centers for Disease Control and Prevention (CDC) website.

What are the symptoms of polio?

Many people infected with the polio virus do not develop symptoms. Some people will have flu-like symptoms that include:

  • Fever
  • Tiredness
  • Nausea
  • Headache
  • Sore throat
  • Stomach pain

A smaller amount of infected people develop serious symptoms that affect the brain and spinal cord. These symptoms include:

  • Infection of the covering of the spinal cord or brain (meningitis).
  • Paralysis or weakness of the arms and legs

In some cases, polio can lead to permanent paralysis and disability. Limb paralysis can improve over time. In some people, new muscle pain and weakness may develop 15 to 40 years later. This is called “post-polio syndrome.”

Who is at risk?

Polio primarily affects unvaccinated children, but anyone who is not fully vaccinated against the virus is at risk of developing severe illness if exposed.

In recent years, global vaccination efforts have significantly reduced the number of polio cases worldwide. Polio is still a concern in countries that do not have access to the vaccine.

International travelers may be at risk depending on their travel location. Make sure you are vaccinated against polio and other diseases before traveling.

Limit the spread of polio

Vaccination is the best way to protect against polio. Children  should be vaccinated against polio as part of the routine childhood vaccine schedule.

If you are traveling outside of the United States, make sure you are up to date on your vaccinations.

In addition to vaccination, it is always important to have good hygiene practices. Alcohol-based sanitizers do not kill poliovirus, so wash your hands often with soap and water. Avoid touching surfaces or objects and then touching your mouth or eyes.

Notifiable Condition

Polio is a notifiable condition for healthcare providers. For more information on identifying and reporting poliovirus, visit the Polio Notifiable Conditions web page.

Polio Vaccine

Who should get the polio vaccine?

The Centers for Disease Control and Prevention recommends all children receive inactivated polio vaccine (IPV) against polio as part of their routine immunization schedule.

Children should receive 4 doses of IPV, with one dose at each of these ages:

  • 2 months
  • 4 months
  • Between 6 to 18 months
  • Between 4 years to 6 years

Children traveling internationally can receive an accelerated IPV vaccination schedule if necessary. Talk to your trusted healthcare provider if this applies to your family.

Adults who have an incomplete or missing polio vaccination series should complete the polio vaccination series with IPV. Talk with your trusted healthcare provider to determine the correct schedule and amount of doses you may need.

Those at increased risk of exposure to polio can get one booster of IPV vaccine. These groups include:

  • Travelers going to countries where polio is present.
  • Laboratory and healthcare workers who handle specimens that may contain polioviruses.
  • Caregivers or healthcare workers who provide care, or have close contact with someone who could be infected with poliovirus.
  • Certain groups or populations at increased risk because of an outbreak when identified by public health authorities.

Some countries use the oral polio vaccine (OPV), a vaccine no longer used in the United States. The OPV vaccine was changed in 2016 so it no longer protects against all types of polio. If you or your child had the OPV vaccine while living in another country talk with your trusted health care provider to see if you need IPV vaccine.

What are the side effects of polio vaccine?

The most common side effect of polio vaccination is a sore spot with redness, swelling, or pain where the shot was given.

This vaccine is continually monitored for safety. The benefits and side effects of this vaccine outweigh the risk of getting polio.

Why is polio vaccine important?

Before vaccines, polio killed or affected many thousands of people each year and many survivors experienced deformed limbs, paralysis, and needed a breathing  machine. Before vaccination in the 1950’s, the United States saw 58,000 cases of polio a year. Six years after the polio vaccine was invented, the United States saw less than 200 cases of polio.

Polio is still happening in other countries and puts travelers at risk. A person infected with polio traveling to the U.S. can infect someone who is not vaccinated.

Vaccine Information Statement

The vaccine information statement (VIS) is given to patients or parents/guardians at the time of vaccination. It explains the benefits and risks of the specific vaccination.

Read the current Polio Vaccine (IPV) VIS from the Centers of Disease Control and Prevention (CDC).

Additional Resources for the Public

Additional Resources for Healthcare Providers

Childhood Vaccine Program

The Washington State Childhood Vaccination Program provides vaccines to children 18 years of age and younger at no cost. Polio vaccine is included in this program.

View participating healthcare providers on the Department of Health’s Vaccine Provider Map (English-only link).

Polio Vaccine Requirement for Schools and Child Cares

Polio vaccination is required for child care and school entry in the state of Washington. Learn more about school and child care immunization requirements by visiting the family friendly school immunization requirements webpage www.doh.wa.gov/vaxtoschool.