Before the development of a vaccine for poliomyelitis, this viral infection was one of the most feared diseases in the United States. or more commonly known as polio, is a disabling and deadly disease caused by the polio virus. The virus is highly contagious, and can spread from person to person from contact with saliva, feces, or air droplets from coughing or sneezing. Polio virus can infect a person’s spinal cord, leading to paralysis. According to the , about 72 percent of people who contract polio will not show any visible symptoms. About 1 in 4 people who contract polio will display flu-like symptoms, such as a sore throat, fever, fatigue, nausea, and headaches. Symptoms like these are usually present for two to five days, then decline. A small percent of those affected by the polio virus infection will develop life-threatening symptoms which affect the brain and spinal cord, such as paresthesia, meningitis, and paralysis.
The virus tended to cause paralysis in the muscles in the chest, leading to severe difficulty breathing, which was associated with high mortality. As a method of treatment, physicians would utilize tank respirators, more commonly known as "iron lungs." This device served as a mechanism of artificial respiration for patients who were unable to properly breathe independently. The only preventative method for protection against polio is a . This vaccine protects children by leading to the development of antibodies that can fight against the polio virus. According to the CDC, about 99 out of 100 children who get the recommended number of doses for the polio vaccine will be protected from disease.
Before 1955, the year the polio vaccine was developed, late summers were known as “” Due to the fear of the spread of the infection, public swimming pools were shut down and people were urged not to sit too close to each other in movie theaters. According to , in 1952, about 60,000 children were infected with the polio virus, leading to thousands being paralyzed, and nearly 3,000 deaths. There were previous epidemics resulting in thousands of deaths in 1894 and 1916. President Franklin D. Roosevelt even had polio 12 years before his presidency. His acknowledgment of his experiences with disease helped put polio in the public eye. In 1946, President Harry Truman declared that polio is a threat to the United States, and made a call for action to eradicate the disease.
was the lead researcher in the discovery of the first successful polio vaccine. In 1947, he was appointed as the director of the Virus Research Laboratory at the University of Pittsburgh School of Medicine. Salk’s belief that his vaccine, which had dead polio virus, could give a person immunity to polio without infecting or killing them, was the controversial and opposed the scientific community’s view of vaccines at the time. Salk administered the vaccine to people who had never contracted polio -- including himself --, and all the recipients developed antibodies for polio in response to the vaccine, displaying no negative side effects.
By 1954, nationwide tests were done on one million children, all ages six to nine. By April 1955, it was announced that the results of these tests showed that the vaccine was both safe and effective. According to , two years before the wide availability of the vaccine, the average number of polio cases in the United States was about 45,000. By 1962, this number dropped to about 910. By 1979, the virus had been eliminated in the United States. According to , as of 2018, the Americas, Europe, Southeast Asia, and the Western Pacific are all polio-free regions of the world. Afghanistan, Nigeria, and Pakistan are the only three remaining countries that consistently report cases of polio in the world.