How it started: The first documented polio epidemic in the United States was in 1894. Outbreaks occurred throughout the first half of the 20th century, primarily killing children and leaving many more paralyzed.
Polio reached pandemic levels in the 1940s. There were more than 600,000 cases of polio in the United States in the 20th century and nearly 60,000 deaths – a death rate of 9.8%. In 1952 alone, there were 57,628 reported cases of polio, resulting in 3,145 deaths.
“Polio was every mother’s scourge,” Benjamin said. “People were afraid of dying of polio.”
Polio was highly contagious: in a household with an infected adult or a child, 90% to 100% of susceptible people would develop evidence in their blood to have also been infected. Polio does not spread through the air – transmission occurs from oral-oral infection (e.g., sharing a drinking glass) or from “what is nicely called hand-faecal,” Paula Cannon, a virology professor at the University of Southern California Keck School of Medicine, told me. “People bake it out and people get it on their hands and they make a sandwich for you.”
Like COVID-19, polio can have devastating long-term effects even if you survived the first infection. President Franklin Roosevelt was among the thousands of people living with permanent polio paralysis. Others spent weeks, years or the rest of their lives in iron lungs.
Precautions were taken during the polio pandemic. Schools and public swimming pools closed. Then, in 1955, a miracle: a vaccine.
A course with two doses of the polio vaccine proved to be about 90% effective – corresponding to the effectiveness of our current COVID-19 vaccines. Vaccine technology was still relatively new and the polio vaccine was not without side effects. A small number of people who got that vaccine got polio from it. Another subgroup of recipients developed Guillain-Barre syndrome, a non-communicable autoimmune disorder that can cause paralysis or nerve damage. A messy batch killed some of the people who received it.
Benjamin said the polio vaccine campaign became a moment of national unity: “Jonas Salk and the people who solved the polio problem were national heroes.”
In 1979, polio was eradicated in the United States.
How it ended: Vaccination