Two little girls in matching gingham jumpers -- Pam is crouching and pulling on her sister Patricia's leg brace -- appeared in a poster for the National Foundation for Infantile Paralysis in the early 1950s. They'd both recovered from polio.
"The story always went that she would loosen my braces, so we could play better, because my legs would be stiff ... I had it worse than she did," said Patricia O'Neil Dryer, now 65 years old and living in St. Cloud, Florida.
The poster is from a time when polio was a crisis in the United States. Today, the disease has been almost entirely eliminated worldwide, and its "poster children" live in remote areas of violence-stricken developing countries.
Health efforts are close to wiping out polio, but two significant challenges remain: money and the operational logistics of getting the vaccine to people who need it.
On the precipice of eradication, it's worth taking a look at how far we've come with polio and what's left to be done.
There have been 96 cases of polio reported worldwide this year, said Dr. Stephen Cochi, a polio specialist at the Centers for Disease Control and Prevention. That represents a two-thirds reduction in cases compared with the same point in 2011. "We're on an acceleration path downward," he said.
Countries that have never been free of the disease are said to have endemic polio, and three remain: Afghanistan, Pakistan and Nigeria. Besides those countries, Chad, which previously had been polio-free, is reporting five cases this year because of the virus crossing the border with Nigeria, Cochi said.
It's going to be hard to get the number of annual cases down to nothing because of difficulties remaining in those few countries, Cochi said.
The World Health Organization has an action plan for the next 18 months that could very well lead to eradication, says Oliver Rosenbauer, spokesman for polio efforts at the organization.
But there's a $945 million funding gap, he said. Already, polio immunization activities in 24 countries have been cut this year.
And then there are logistical issues of getting vaccines to the children who need them most.
In northwest Pakistan, the Taliban have imposed a ban on polio vaccinations, which could affect about 280,000 children who live in tribal areas in the region, according to the World Health Organization.
The local Taliban militants prohibited the vaccines to protest American drone strikes in the area. And this month, health workers and volunteers did not achieve their goal of immunizing children in North and South Waziristan.
When polio was in the United States
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