About Polio in the United States

Key points

  • Vaccination has helped eliminate wild poliovirus in the United States.
  • Maintaining high immunity (protection) against polio through vaccination is the best way to continue keeping people safe from polio.
  • The polio vaccine is safe and effective.

What it is

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

The best way to keep people safe is through vaccination. This maintains a high level of protection (also called immunity) in the population.

Signs and symptoms

Most people who get infected with poliovirus will not have any visible symptoms.

About 1 out of 4 people with poliovirus infection will have flu-like symptoms that can include:

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

These symptoms usually last 2 to 5 days, then go away on their own.

Serious symptoms

A smaller proportion of people with poliovirus infection will develop more serious symptoms that affect the brain and spinal cord:

  • Meningitis (infection of the covering of the spinal cord and/or brain)—occurs in about 1 to 5 out of 100 people with poliovirus infection, depending on virus type.
  • Paralysis (can't move parts of the body) or weakness in the arms, legs, or both—occurs in about 1 out of 200 people to 1 in 2000 people, depending on virus type.

Paralysis is the most severe symptom associated with poliovirus because it can lead to permanent disability and death. Between 2 to 10 out of 100 people who have paralysis from poliovirus infection die, because the virus affects the muscles that help them breathe

Call your doctor immediately if:‎

You think you or someone in your family has symptoms of polio, please call your healthcare provider right away or go to an emergency room.

Post-polio syndrome

Post-polio syndrome (PPS) is a condition that can affect polio survivors decades after they recover from their initial poliovirus infection. Unlike poliovirus, PPS is not contagious.

PPS affects between 25 and 40 out of every 100 polio survivors. Starting about 15 to 40 years after the initial infection, people affected by PPS can begin experiencing a set of health problems such as:

  • Muscle weakness
  • Feeling tired (mental and physical fatigue)
  • Joint pain

Some people with PPS have only minor symptoms, while others develop more visible muscle weakness and atrophy (a decrease in muscle size). PPS is rarely life-threatening, but the symptoms can make it difficult for an affected person to function independently.

How it spreads

You can spread the virus for days!‎

An infected person can spread the virus to others immediately before and up to 2 weeks after symptoms appear. People who don't have symptoms can still pass the virus to others and make them sick.

Poliovirus is very contagious. It lives in an infected person's throat and intestines and spreads through person-to-person contact. It can also contaminate food and water in unsanitary conditions.

Poliovirus only infects people, entering the body through the mouth. You can ger polio from:

  • Contact with the feces (poop) of an infected person
  • Droplets from a sneeze or cough of an infected person (less common)


There are two types of vaccine that can prevent polio:

  • Inactivated poliovirus vaccine (IPV)—given as an injection in the leg or arm, depending on the patient's age. Only IPV has been used in the United States since 2000.
  • Oral poliovirus vaccine (OPV)—still used throughout much of the world.

Polio vaccine protects children by preparing their bodies to fight the poliovirus. Almost all children (more than 99%) who get all the recommended doses of the inactivated polio vaccine will be protected.

Talk to your healthcare provider if you have any concerns about polio or your vaccination status. Your provider can help you understand your options.

In addition to protecting yourself with the vaccine, practice good hand hygiene. Wash hands often with soap and water. Note that alcohol-based hand sanitizers do not kill poliovirus.

Testing and diagnosis

Diagnostic testing can detect poliovirus in specimens from the throat, feces (stool), and occasionally cerebrospinal fluid (CSF). Testing works by isolating the virus in cell culture or by detecting the virus by polymerase chain reaction (PCR).

Treatment and recovery

There is no cure for paralytic polio and no specific treatment.

Physical or occupational therapy can help with arm or leg weakness caused by polio. Therapy might also improve long-term outcomes, especially if implemented early in the course of illness.

Healthcare providers should consider consulting neurology and infectious disease experts to:

  • Discuss possible treatments.
  • Recommend certain interventions on a case-by-case basis.

Getting vaccinated

Since the year 2000, the inactivated polio vaccine (IPV) is the only polio vaccine used in the United States. This vaccine is given as a shot in the arm or leg. It is very safe, and it protects against severe polio disease, including paralysis.


Most adults in the United States were likely vaccinated against poliovirus during childhood. However, some adults might not have received the full vaccine protection.

If you know or suspect that you are unvaccinated or incompletely vaccinated, you should receive polio vaccination.

If you are fully vaccinated but at increased risk of poliovirus exposure, you may receive 1 lifetime booster dose of IPV. Increased risk includes things like planning to travel to other countries with a higher risk of poliovirus transmission.


For best protection, children should get 4 doses of polio vaccine. Ideally, your child should receive a dose at the following ages:

  • 2 months
  • 4 months
  • 6–18 months
  • 4–6 years

IPV may sometimes be given in the same shot with other vaccines (also called combination vaccines). You can ask your child's doctor about this option.

Where to get polio vaccine

Parents, work with your child's doctor on doses and timing for the polio vaccine. If you don't have health insurance or your insurance doesn't cover your child's vaccines the Vaccines for Children Program might help. Other resources:

Traveling to another country

When you are planning to travel to another country, include recommended vaccinations in your plans. Make sure you get your travel vaccinations well before your departure date to ensure complete protection. See your healthcare provider for more information.