Most people with polio have no symptoms; minor symptoms such as limb pain, fatigue and nausea affect about 4% to 8% of patients, according to the CDC. Fewer than 1% of cases lead to patients becoming permanently paralyzed, usually in the legs. Between 5% and 10% of paralyzed patients die when their respiratory muscles become paralyzed, too.
Human beings have been living with polio for thousands of years, Cochi said. There's evidence from ancient Egypt that paralytic polio existed there and even infected royalty. But it wasn't described clinically until 1789.
The United States saw its first polio outbreak in 1894 in Vermont, with 132 cases, according to the Smithsonian. As the population became more urbanized in the early 20th century, more outbreaks occurred. President Franklin Delano Roosevelt contracted the disease at age 39 in 1921.
Although no cure was developed, a device called an iron lung was invented to help people with the disease breathe. The patient would lie on a bed inside a cylindrical tank, and the machine helped some people become able to breathe again on their own. This device cost about $1,500 in the 1930s -- about what a home would cost then, according to the Smithsonian.
Eileen Grotzsky of Queens, New York, 65, was one patient who had to use an iron lung as a young child. By that point, she was paralyzed from the neck down. "I was one of the lucky ones. My left leg was bad; my right leg was pretty good," she said.
John Kressaty of Mesa, Arizona, now 64, was 7 when he contracted polio. In his hospital ward, there were only about seven iron lungs -- not enough to go around. He underwent a treatment developed by an Australian nun named Sister Elizabeth Kenny that consisted of "hot, steamed, woolen cloth over your body" and physical therapy. He slept on a mattress with a plywood board underneath it so his spine wouldn't curve.
Kressaty feared he would never be able to move his arms and legs again.
"You're thinking, 'Is that what I'm going to go through for the rest of my life?' " he remembers.
Fortunately, Kressaty didn't have any major physical limitations when he recovered. He went back to school but couldn't fully participate in gym class, and his left side was weaker than his right. By 18, he was regaining muscle tone and played college basketball for a year.
"I got through most of life not with any restrictions," he said. "I was very lucky."
In 1938, Roosevelt founded the National Foundation for Infantile Paralysis, an organization known today as the March of Dimes Foundation, to fight polio. The organization funded the two vaccines -- created by Jonas Salk and Albert Sabin -- that would lead to the protection of most of the world against polio.
The vaccine was eagerly awaited because, according to the CDC, about 35,000 people annually became disabled because of polio in the U.S. in the 1940s and '50s.
Salk's vaccine, developed in the 1950s, involved injecting a virus that was "killed," while Sabin's vaccine -- which he worked on in the 1960s and which was administered orally -- contained a weakened version of polio.
The Sabin vaccine actually helped boost immunity in communities beyond the individual because people shed the weakened virus in their feces. It came to replace the Salk vaccine in many places between 1963 and 1999, according to the Smithsonian. But the injected killed virus version is what's given in the United States today because of the rare instances of people developing polio from the oral vaccine.
Polio was declared eradicated in the United States in 1979. But the vaccination effort doesn't stop.
"In the U.S., where there's no problem anymore, we still want to have (the) population protected," said Michael Katz, senior advisor and interim medical director of the March of Dimes.
Children should receive four doses of inactivated polio vaccine, delivered as an injection, at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years, according to the CDC.
Most American adults were vaccinated as children and don't need another dose. But people may need additional protection if they are traveling to high-risk countries, handle poliovirus specimens in a laboratory or have close contact with a person who has polio.
Polio primarily spreads from person to person -- through coughing and sneezing -- or through fecal contamination. The particles are large enough that the risk of contracting polio in the air is momentary, and on a surface like a desk or a chair, it can last an hour or two. But in sewage, it can last for weeks or even months.
Human beings have been living with polio for thousands of years, Cochi said. There's evidence from ancient Egypt that paralytic polio existed there and even infected royalty. But it wasn't described clinically until 1789.
The United States saw its first polio outbreak in 1894 in Vermont, with 132 cases, according to the Smithsonian. As the population became more urbanized in the early 20th century, more outbreaks occurred. President Franklin Delano Roosevelt contracted the disease at age 39 in 1921.
Although no cure was developed, a device called an iron lung was invented to help people with the disease breathe. The patient would lie on a bed inside a cylindrical tank, and the machine helped some people become able to breathe again on their own. This device cost about $1,500 in the 1930s -- about what a home would cost then, according to the Smithsonian.
Eileen Grotzsky of Queens, New York, 65, was one patient who had to use an iron lung as a young child. By that point, she was paralyzed from the neck down. "I was one of the lucky ones. My left leg was bad; my right leg was pretty good," she said.
John Kressaty of Mesa, Arizona, now 64, was 7 when he contracted polio. In his hospital ward, there were only about seven iron lungs -- not enough to go around. He underwent a treatment developed by an Australian nun named Sister Elizabeth Kenny that consisted of "hot, steamed, woolen cloth over your body" and physical therapy. He slept on a mattress with a plywood board underneath it so his spine wouldn't curve.
Kressaty feared he would never be able to move his arms and legs again.
"You're thinking, 'Is that what I'm going to go through for the rest of my life?' " he remembers.
Fortunately, Kressaty didn't have any major physical limitations when he recovered. He went back to school but couldn't fully participate in gym class, and his left side was weaker than his right. By 18, he was regaining muscle tone and played college basketball for a year.
"I got through most of life not with any restrictions," he said. "I was very lucky."
In 1938, Roosevelt founded the National Foundation for Infantile Paralysis, an organization known today as the March of Dimes Foundation, to fight polio. The organization funded the two vaccines -- created by Jonas Salk and Albert Sabin -- that would lead to the protection of most of the world against polio.
The vaccine was eagerly awaited because, according to the CDC, about 35,000 people annually became disabled because of polio in the U.S. in the 1940s and '50s.
Salk's vaccine, developed in the 1950s, involved injecting a virus that was "killed," while Sabin's vaccine -- which he worked on in the 1960s and which was administered orally -- contained a weakened version of polio.
The Sabin vaccine actually helped boost immunity in communities beyond the individual because people shed the weakened virus in their feces. It came to replace the Salk vaccine in many places between 1963 and 1999, according to the Smithsonian. But the injected killed virus version is what's given in the United States today because of the rare instances of people developing polio from the oral vaccine.
Polio was declared eradicated in the United States in 1979. But the vaccination effort doesn't stop.
"In the U.S., where there's no problem anymore, we still want to have (the) population protected," said Michael Katz, senior advisor and interim medical director of the March of Dimes.
Children should receive four doses of inactivated polio vaccine, delivered as an injection, at ages 2 months, 4 months, 6 to 18 months, and 4 to 6 years, according to the CDC.
Most American adults were vaccinated as children and don't need another dose. But people may need additional protection if they are traveling to high-risk countries, handle poliovirus specimens in a laboratory or have close contact with a person who has polio.
Polio primarily spreads from person to person -- through coughing and sneezing -- or through fecal contamination. The particles are large enough that the risk of contracting polio in the air is momentary, and on a surface like a desk or a chair, it can last an hour or two. But in sewage, it can last for weeks or even months.
