# data[].attributes.attachment_link.provider_name
Centers for Disease Control and Prevention

# data[].attributes.attachment_link.readable_text
Thanks to a successful vaccination program, the United States has been polio-free since 1979.

But poliovirus is still a threat in some countries.

Get your child vaccinated on schedule and be part of the success story.

Polio was once one of the most feared diseases in the U.S. In the early 1950s, before polio vaccines were available, polio outbreaks caused more than 15,000 cases of paralysis each year. Following introduction of vaccines-specifically, trivalent inactivated poliovirus vaccine (IPV) in 1955 and trivalent oral poliovirus vaccine (OPV) in 1963-the number of polio cases fell rapidly to less than 100 in the 1960s and fewer than 10 in the 1970s.

In the late 1940s, polio outbreaks in the U.S. increased in frequency and size, disabling an average of more than 35,000 people each year. Parents were frightened to let their children go outside, especially in the summer when the virus seemed to peak. Travel and commerce between affected cities were sometimes restricted. Public health officials imposed quarantines (used to separate and restrict the movement of well people who may have been exposed to a contagious disease to see if they become ill) on homes and towns where polio cases were diagnosed.

Thanks to the polio vaccine, dedicated health care professionals, and parents who vaccinate their children on schedule, polio has been eliminated in this country for more than 30 years. This means that there is no year-round transmission of poliovirus in the United States.

Since 1979, no cases of polio have originated in the U.S.

However, the virus has been brought into the country by travelers with polio. The last time this happened was in 1993.

It takes only one traveler with polio to bring the disease into the United States. People most at risk are:

The best way to keep the United States polio-free is to maintain high immunity (protection) against polio in the population through vaccination.

Page last reviewed:

# data[].attributes.attachment_link.description
Thanks to a successful vaccination program, the United States has been polio-free since 1979. But poliovirus is still a threat in some countries. Get your child vaccinated on schedule and be part of the success story. Polio was once one of the most feared diseases in the U.S.

# data[].attributes.body
Polio is a viral disease that is caused by the poliovirus also known as poliomyelitis. This disease can cause paralysis due to the virus attacking the nerve cells in the brain stem. It is most common in children and is spread by food and water contaminants.

# data[].attributes.body
Poliomyelitis is the virus that causes the symptoms of polio

# data[].attributes.body
The image above is a great resource when it comes to understanding the symptoms of polio in children. This also gives great ways to prevent the spread and infection of the virus. Some other complications that may be caused because of the infections is paralysis, muscle weakness and slow growth.

# data[].attributes.attachment_link.readable_text
Overview

Polio is an illness caused by a virus that mainly affects nerves in the spinal cord or brain stem. In its most severe form, polio can lead to a person being unable to move certain limbs, also called paralysis. It can also lead to trouble breathing and sometimes death. The disease also is called poliomyelitis.

A vaccination effort throughout the world has led to only a small number of cases to occur around the world in recent years. But poliovirus still spreads within areas with low vaccination rates.

The U.S. Centers for Disease Control and Prevention (CDC) publishes travel notices of countries where there is a higher risk of polio. Countries at a higher risk of polio are generally in Africa, the Middle East, and southern and central Asia.

Vaccinated adults who plan to travel to an area where polio is spreading should get a booster dose of inactivated poliovirus vaccine (IPV). Immunity after a booster lasts a lifetime.

Symptoms

Most people infected with the virus that causes polio, called poliovirus, don't get symptoms.

Abortive polio

About 5% of people with the poliovirus get a mild version of the disease called abortive poliomyelitis. This leads to flu-like symptoms that last 2 to 3 days. These include:

Nonparalytic polio

A more severe form of the disease, called nonparalytic polio, affects about 1% of those infected. While the illness lasts longer than a few days, it doesn't cause paralysis. Besides having more-severe flu-like symptoms, nonparalytic polio symptoms may include:

Neck pain or stiffness

Aches or stiffness in the arms or legs

Severe headache

A second phase of symptoms may follow, or a person may seem to be getting better for a few days before a second phase starts. These symptoms include:

Stiffness of the spine and neck

Decreased reflexes

Muscle weakness

Paralytic polio

This most serious form of the disease is rare. The disease begins much like nonparalytic polio. But it progresses to more-severe signs and symptoms, including:

Intense pain

Extreme sensitivity to touch

Tingling or pricking sensations

Muscles spasms or twitching

Muscles weakness progressing to a limp paralysis

Any combination of limbs may experience paralysis. But paralysis of one leg is most common, followed by paralysis of one arm.

Depending on the severity of disease, other signs or symptoms may include:

Paralysis of muscles involved in breathing

Difficulty swallowing

Post-polio syndrome

Post-polio syndrome is the appearance of new signs or symptoms or the progression of problems. This usually happens decades after having polio. Common signs and symptoms include:

Progressive muscle or joint weakness and pain

Fatigue

Muscle wasting

Breathing or swallowing problems

Sleep-related breathing disorders, such as sleep apnea

Lowered tolerance of cold temperatures

When to see a doctor

Signs and symptoms of polio are similar to other viral diseases that affect the nervous system. It's important to get a timely and accurate diagnosis.

If you had polio before, see your health care provider if you have new or worse signs or symptoms.

Causes

Polio is caused by the poliovirus. It mainly targets nerve cells in the spinal cord and brain stem that control muscle movement. Nerve cells controlling sensation are generally not affected.

The naturally-occurring poliovirus, called the wild-type poliovirus, has been eliminated in most countries and causes few cases of polio. Another version of the virus, called the vaccine-derived poliovirus (VDPV), is more widespread and now causes most infections worldwide. VDPV exists mainly in a few countries that use an oral vaccine with a weakened poliovirus.

The weakened virus in the oral vaccine doesn't itself cause polio, and vaccinated people rarely contract VDPV. Instead, VDPV is a new version of the virus that develops within a community or region where not enough people are vaccinated.

Even though the weakened virus in the oral vaccine doesn't cause illness, it can spread. If most people in a community are vaccinated, the spread of the weakened virus is controlled. If many people aren't vaccinated, the weakened virus can move through a community for a long time. This gives the virus the chance to change, or mutate, and behave like the wild-type virus that causes illness.

Infections from VDPV have been reported in the United States. In each case, the person was either not vaccinated or had a significantly weakened immune system. One case in New York in 2022 was in a county with a lower-than-average polio vaccination rate. Samples from wastewater showed that VDPV was spreading in some communities.

Since 2000, polio vaccination in the United States has used an injected vaccine with an inactivated poliovirus that doesn't create the risk for VDPV.

How polio spreads

People carrying the poliovirus - even people who don't get sick - can pass along the virus in feces, also called stool, or droplets from sneezing or coughing. The virus enters another person through the mouth. The virus can spread easily. For example, the virus can spread if people haven't washed their hands after coughing, using the toilet or before eating.

The virus also may be in water contaminated with feces carrying the poliovirus.

Risk factors

Polio mainly affects children. But anyone who hasn't been vaccinated is at risk of getting the disease.

Complications

Severe disease that affects the ability to breathe can cause death. Long-term complications for people who recover may include:

Permanent paralysis

Muscle shortening that causes deformed bones or joints

Chronic pain

Post-polio syndrome

Prevention

The most effective way to prevent polio is vaccination.

Polio vaccine

The CDC recommends four doses of inactivated poliovirus vaccine (IPV) at the following ages:

2 months

4 months

Between 6 and 18 months

Between ages 4 and 6 when children are just entering school

If your child is missing a dose, talk to your health care provider about a catch-up schedule for vaccination.

Adult vaccination

In the U.S., most adults have immunity to the poliovirus because of childhood vaccination. And U.S. adults have little chance of being exposed to the virus. But adults who are traveling to or living in a region with high rates of spreading poliovirus should receive more vaccinations.

If you had a complete course of vaccination, you should get a one-time IPV booster. You should get three IPV doses if you aren't vaccinated, didn't receive a complete vaccination or are unsure of your vaccination status.

The IPV schedule for adults is a second dose 1 to 2 months after the first dose. Then the third dose is 6 to 12 months after the second dose. Talk to your health care provider if you know you have an incomplete vaccination history.

Vaccine safety

IPV is safe for people with weakened immune systems, although it's not certain how protective the vaccine is in cases of severe immune deficiency. Common side effects are pain and redness at the injection site.

IPV can cause an allergic reaction in some people. Because the vaccine has trace amounts of the antibiotics streptomycin, polymyxin B and neomycin, it may cause a reaction in people allergic to one of these antibiotics. A person who has a severe reaction to a first dose of IPV won't get more doses.

Signs and symptoms of an allergic reaction usually occur within minutes to a few hours after the shot. Watch for:

Skin reactions, including hives and itching and flushed or pale skin

Low blood pressure (hypotension)

Narrowing of the airways and a swollen tongue or throat, which can cause wheezing and trouble breathing

A weak and fast pulse

Nausea, vomiting or diarrhea

Dizziness or fainting

If you or your child has an allergic reaction after any vaccination, get medical help right away.

# data[].attributes.attachment_link.description
Learn more about this contagious viral illness that affects the nervous system. Severe disease can lead to paralysis, trouble breathing and sometimes death.

# data[].attributes.body
There are two variations of the vaccine that can help prevent polio. The first is an inactive vaccine and the second is a live but weak version of the virus. The development of these vaccines has caused the near-complete eradication of the poliovirus. Since 1979 there have been no polio cases that have originated in the US. Many places around the world have added the polio vaccine to the regiment that is given to new born children.

# data[].attributes.body
Mayo Foundation for Medical Education and Research. (2020, December 1). Polio. Mayo Clinic. Retrieved December 5, 2021, from https://www.mayoclinic.org/diseases-conditions/polio/symptoms-causes/syc-20376512.

About Jonas Salk. Salk Institute for Biological Studies. (2015, November 15). Retrieved December 5, 2021, from https://www.salk.edu/about/history-of-salk/jonas-salk/.

Centers for Disease Control and Prevention. (2021, September 28). What is polio? Centers for Disease Control and Prevention. Retrieved December 5, 2021, from https://www.cdc.gov/polio/what-is-polio/index.htm.

Polio (poliomyelitis): What is it, symptoms, causes & vaccine. Cleveland Clinic. (n.d.). Retrieved December 5, 2021, from https://my.clevelandclinic.org/health/diseases/15655-polio.

Polio (poliomyelitis). Johns Hopkins Medicine. (n.d.). Retrieved December 5, 2021, from https://www.hopkinsmedicine.org/health/conditions-and-diseases/poliomyelitis-polio#:~:text=How%20is%20polio%20diagnosed%3F,your%20spinal%20fluid%20to%20examine.

# data[].attributes.body
Dr. Jonas Salk and his team at the University of Pittsburg developed the first effective polio vaccine in 1952
Additional information on Dr.Sulk
https://www.salk.edu/about/history-of-salk/jonas-salk/

# data[].attributes.body
The most common way that a polio infection is diagnosed is by having a physician look at the patients stool and performing a swab of the patients throat. After developing the culture the poliomyelitis virus can be identified.

# data[].attributes.body
Treatment: There is no cure currently for polio infection so the best that a person could do for treatment of the infection is symptom control.
Vaccine: The most common vaccine that is used worldwide currently is the inactivated polio vaccine (OPV)
In the US we use a similar vaccine that is injected (IPV) This is slightly different than the one that is used OPV in the fact that the OPV is given orally.