Though most people recovered quickly from polio, some suffered temporary or permanent paralysis and even death. Many polio survivors were disabled for life. They were a visible, painful reminder to society of the enormous toll this disease took on young lives. Polio is the common name for poliomyelitis, which comes from the Greek words for grey and marrow , referring to the spinal cord, and the suffix — itis , meaning inflammation.
Poliomyelitis , shortened, became polio. For a time, polio was called infantile paralysis, though it did not affect only the young. Polio is caused by one of three types of poliovirus which are members of the Enterovirus genus. These viruses spread through contact between people, by nasal and oral secretions, and by contact with contaminated feces.
Poliovirus enters the body through the mouth, multiplying along the way to the digestive tract, where it further multiplies. Albert Sabin , held that only a live-virus vaccine, which involved using a weakened form of the polio virus to stimulate antibodies, could work. That theory stemmed from work by the physician Edward Jenner , who in the s determined that milkmaids exposed to the cowpox virus-laden pus of cowpox-infected cattle did not catch smallpox.
Jonas Salk , a doctor and scientist based at the University of Pittsburgh, on the other hand, believed a killed virus, which would completely lose its infectious qualities, could still trick the body into creating protective antibodies against the polio virus.
A nonprofit organization, the National Infantile Paralysis Foundation , funded and thus directed the polio vaccine quest. Established by President Franklin D. As part of this fundraising effort, Americans were called upon to send dimes to the White House in what became known as the March of Dimes.
By , Salk and his team had shown their experimental vaccine worked — first on monkeys in their lab, then on children who already had polio at the D. Watson Home for Crippled Children, and then on a small group of healthy children in Pittsburgh.
One of the largest field trials in medical history soon followed. It began on April 23, Some , children got the Salk polio vaccine or a placebo, and 1. President Dwight D. But poliovirus is still a threat in some countries. It takes only one traveler with polio to bring the disease into the United States. The best way to keep the United States polio-free is to maintain high immunity protection in the U.
Vaccine recommendations and contraindications; composition, dosage, and administration; handling and storage. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Vaccines and Preventable Diseases. Section Navigation. In alone, there were 58, new cases of polio and 3, deaths from the disease in the U.
Related: The 12 deadliest viruses on Earth. As medical experts worked to understand the virus, they discovered that it could infect people without causing symptoms. In a study published in the American Journal of Hygiene , researchers reported that the prevalence of poliovirus in New York City sewage water meant that there were an estimated asymptomatic cases of polio for every symptomatic, or paralytic, case of the disease at the time.
Today, more recent research suggests that 72 out of people who are infected with the virus will never experience symptoms, and about 1 in 4 infected people will experience only flu-like symptoms that last between 2 and 5 days before going away on their own, according to the CDC. In the late s, researchers learned that infected individuals shed the virus in feces for several weeks, whether or not they had symptoms of the disease. Researchers have since confirmed that infected, but asymptomatic, people can still shed the virus and make people sick.
People who do become sick can shed the virus immediately before they show symptoms and for up to 2 weeks after their symptoms appear, according to the CDC. Researchers began working on a polio vaccine in the s, but early attempts were unsuccessful. An effective vaccine didn't come around until , when Jonas Salk introduced his inactivated polio vaccine IPV.
In , he was awarded a research grant from President Franklin D. Roosevelt had contracted polio in at age 39, and the disease left him with both legs permanently paralyzed. In , five years into his presidency, Roosevelt helped to create the National Foundation for Infantile Paralysis to raise money and deliver aid to areas experiencing polio epidemics. Thanks to the work of researchers before him, Salk was able to grow poliovirus in monkey kidney cells.
He then isolated the virus and inactivated it with formalin, an organic solution of formaldehyde and water that is commonly used as a disinfectant and embalming agent. Brodie tested his vaccine on 20 monkeys and then on schoolchildren, but the results were poor and Brodie didn't test any further. Related: 5 dangerous myths about vaccines.
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