Polio

What is polio?

Polio is a serious contagious disease that is caused by a virus. It can paralyze you or lead to death. Polio, also called poliomyelitis, spreads easily from contact with someone who has the virus. A vaccine can protect you and your child from getting polio, but there is no cure for a person who gets the disease.

How polio is contracted and spread

Polio can be spread from coughing or sneezing, in saliva, or in stool (feces). It is very contagious. The virus that causes the disease can also live in food and drink, as well as on surfaces that a sick person has infected. The polio virus enters through the mouth and replicates in the throat and intestinal tract.

Most people don’t feel sick when they have polio, so they don’t know they are spreading it. Anyone who is not up to date with their polio vaccine is at risk of getting the disease.

Polio symptoms

People who have polio usually don’t notice any symptoms. Some people will feel like they have a flu for two to five days. When mild symptoms do show up, it’s usually three to six days after infection.

In severe cases, polio causes weakness or even paralysis (not being able to move your arms, legs or other muscles) starting one to three weeks after catching the disease. Someone who is paralyzed by the disease will be put on a ventilator if the muscles they use to breathe stop working. Before modern ventilators were used, these patients would have to breathe using an “iron lung,” which was a cylinder that enclosed their whole body except their head.

Polio vaccine

Getting the polio vaccine is the only way to protect yourself from becoming sick in case you’re exposed to the virus. There is no cure if you get the disease.

The polio shot used in the United States doesn’t contain any live virus and can’t cause the disease. But a polio shot can have side effects, which are usually mild. The most common one is redness or pain in the arm or leg where you get the shot. See a doctor if you notice hives, trouble breathing, shock or faintness after getting the vaccine.

Polio vaccine history

Polio killed or paralyzed more than half a million people worldwide every year before we found a way to prevent the disease. Then in 1954, an American doctor, Jonas Salk, created the first polio vaccine and first gave it to himself and his family.

Billions of children around the world have gotten the polio vaccine in the past 70 years.

Polio vaccine effectiveness

The polio vaccine is extremely effective. Since the vaccine was introduced, cases of polio have dropped more than 99% around the world. Almost everybody who gets all doses of the vaccine avoids severe disease.

Even though the polio vaccine has nearly eradicated the disease, the disease is highly contagious and can be spread very easily. That’s why it’s still important for children to get the polio vaccine. Even one person who travels someplace where there is polio can easily spread the disease when they get home.

Polio vaccine schedule

All children should get the polio vaccine unless they are allergic to certain medicines, like neomycin, streptomycin and polymyxin B.

Children get the polio vaccine in four shots given at different ages:

• Dose 1: When they are 2 months old
• Dose 2: When they are 4 months old
• Dose 3: When they are 6 to 18 months old
• Dose 4 (booster shot): When they are 4 to 6 years old

Adults should get the polio vaccine if they weren’t vaccinated when they were children or if they didn’t get all four doses. You can get one lifetime booster shot if you’re someone who has a higher chance of being around polio, like some travelers or health care workers.

Polio FAQ

Is polio a virus?

Polio is caused by a virus that spreads from someone who has the disease.

When was the polio vaccine invented?

Dr. Jonas Salk invented the polio vaccine in the early 1950s, and tested it on himself and his own family in 1954.

What are polio drops​?

Polio drops are a form of vaccine that children get through drops in the mouth instead of shots in some parts of the world. Polio drops stopped being used in the United States in January 2000.

Is polio eradicated?

Though polio has been nearly eliminated in most of the world, polio has not been completely eradicated. In 2022, the United States had its first case of polio in almost 30 years when an unvaccinated traveler came into the country with the disease.