Polio

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Polio Overview

What is polio?

Polio is a disabling and life-threatening disease caused by the poliovirus. Most people will not have visible symptoms, but a quarter of people will experience flu-like symptoms. A smaller amount of people will develop meningitis and paralysis. The disease is spread by contact with infected poop, or through droplets from coughing or sneezing.

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

What are the symptoms of polio?

Most people do not experience visible symptoms from polio infection. A quarter of people infected will have flu-like symptoms for 2 to 5 days:

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

A smaller amount of people will develop more serious symptoms that affect the brain and spinal cord:

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

If someone had paralytic polio as a child or young adult but recovered some or all movement of limbs, they can become weaker in late adulthood. This is called post-polio syndrome (PPS).

Who is at risk?

Polio has been eliminated from most of the world, but it still occurs in some countries. Travelers to countries with an increased risk of exposure to poliovirus are more at risk.

Those who are not vaccinated against polio are at increased risk if they are exposed.

Limit the spread of polio

The best way to protect yourself from polio is to get vaccinated. Travelers going to countries with increased risk of polio may be required to show proof of polio vaccination.

The oral poliovirus vaccine (OPV) has been used in many countries to protect against polio disease. In rare instances, the weakened virus in OPV may mutate in immune compromised individuals and cause polio disease. The OPV vaccine is no longer given in the United States. Inactivated polio vaccine (IPV), the vaccine used in the United States, does not cause this as the virus used in the vaccine is not live.

Polio Vaccine

When do people get polio vaccine?

People who have never been vaccinated should get the inactivated polio vaccine (IPV).

In children, one dose of vaccine should be given at the following ages:

  • 2 months of age
  • 4 months of age
  • 6 through 18 months of age
  • 4 through 6 years of age

Children who have not started their polio vaccination series or who are delayed in getting all recommended doses should start right away or finish the series following the recommended catch-up schedule.

There is an accelerated vaccine schedule for those children traveling to a country where the risk of polio is greater. Read more on CDC’s polio vaccine page.

People vaccinated outside of the United States with the newer bivalent oral polio vaccine (OPV) will still need to be vaccinated with IPV to be considered fully protected. Those with questionable documentation should be re-vaccinated.

Most adults in the United States are assumed protected against polio. However, if adults are known or suspected to be unvaccinated, they should complete the IPV polio vaccination series.

Adults at higher risk of exposure to poliovirus may receive one lifetime IPV booster. This includes:

  • Travelers to polio-endemic countries.
  • Laboratory and healthcare workers handling poliovirus specimens.
  • Healthcare workers and caregivers who have close contact with someone who could be infected with poliovirus.
  • Groups identified by public health authorities considered at increased risk due to an outbreak.

Read more about polio vaccination recommendations for adults.

What are the side effects of polio vaccine?

Most people experience minor or no side effects. The most common side effects of inactivated polio vaccine (IPV) include:

  • A sore spot with redness, swelling or pain where the vaccine 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?

Polio was once one of the most feared diseases. Thanks to vaccination, wild poliovirus has been eliminated in the United States.

In 2022, New York had a patient hospitalized with limb weakness from vaccine-derived polio disease, and the virus was found in wastewater samples. Wastewater samples can help us understand if other people may have the disease. Vaccine-derived polio rarely happens in people who receive oral polio vaccine (OPV), which has not used in the United States since 2000.

Because polio is not eliminated across the world, it is important to get polio vaccine to protect yourself and your community.

Vaccine Information Statement and Resources

The Vaccine Information Statement (VIS) is given to parents/guardians at the time of vaccination. It explains the benefits and risks of the specific vaccination.

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

Additional resources for the public

What is polio? (CDC)

Additional resources for healthcare providers

Polio Information Page for Healthcare Providers (CDC)

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 health care providers on the Department of Health’s Vaccine Provider Map.

Polio Vaccine Requirement for Schools

Polio vaccine is required for child care and preschool entry in the state of Washington. Learn more about school and child care immunization requirements by visiting the family friendly school immunization requirements web page.