Jonas Salk and the Search for a Polio Vaccine

In the early 1950s, summer brought an invisible threat to many American communities. Outbreaks of polio sometimes caused swimming pools to close and families to keep children away from crowds. People could not see the virus that caused the disease, but they could see the harm it sometimes left behind.

Jonas Salk, a doctor and researcher born on October 28, 1914, helped change that. He and his team worked to develop a vaccine that would protect people from polio before they became sick.

A disease that worried families

Polio is caused by a virus that spreads from person to person. Many infected people have no symptoms, while others may feel as if they have a mild illness. In some cases, however, the virus attacks the nervous system. This can cause paralysis, a loss of the ability to move parts of the body. If muscles needed for breathing are affected, polio can be deadly.

During outbreaks, no one could easily tell which infected people would become seriously ill. Scientists wanted to prevent the disease rather than wait until patients needed care.

Training the body's defenses

The body's immune system helps fight germs. After it encounters a virus, it can make proteins called antibodies that recognize that virus. A vaccine gives the immune system a safer way to prepare its defenses.