Jonas Salk Discovers First Polio Vaccine

Heartbreaking posters of children on crutches or in iron lungs, the machines that helped those lungs were paralyzed to breathe, circulated during the polio outbreaks of the 1950’s.

Another medical advancement that impacted American life occurred in 1955, when Jonas Salk discovered the first polio vaccine. Earlier, in 1921, outbreaks of poliomyelitis began to plague America. This virus enters the body through the nose or mouth and travels to the intestines, where it incubates (Maybury). A few days later, patients may be asymptomatic or show flu-like symptoms, but all patients can pass the disease on to others at this stage. The virus next enters the bloodstream, and the body must produce antibodies to destroy it (Maybury). In most cases the patient can produce antibodies to stop the virus and acquire lifelong immunity; however, one percent of infected people develop the paralytic form of polio. In these cases, the virus reaches the brain and spinal cord where it multiplies and obliterates nerve tissue (Maybury). The disease becomes either spinal, affecting the limbs, or bulbar, affecting the lungs so that patients cannot breathe. Polio could be spread through contact with infected feces or through infected droplets traveling through the air, in food, or in water (Maybury).

President Franklin Roosevelt, who suffered from the spinal paralytic form of polio, led the fight against the disease by boosting public awareness and promoting research for a cure. Although polio never annihilated vast quantities of the American population as influenza did, it was a fearsome and highly contagious disease that affected both the rich and poor and occurred in terrifying outbreaks (Maybury). Before the twentieth century, immunity to the disease was developed primarily during infancy because sanitation conditions were poor and infants were frequently exposed to polioviruses. Ironically, when hygiene methods improved, infants no longer developed antibodies to fight the virus and were at risk to contract the disease in later childhood and adulthood (Maybury). Children were the most susceptible and parents panicked, keeping their children from schools and other public facilities.

In 1952, Jonas Salk produced a successful vaccine using a mixture of the three types of the virus, which was followed by immense clinical trials of the vaccine in the United States. The results of the trials were dramatic – cases of polio fell enormously in the vaccinated test groups (Maybury). In 1955, the government granted permission for the vaccine to be distributed to children. In 1960, there were 2,525 cases of paralytic polio in the United States; by 1965, the number dropped to 61. There has not been a single case of polio in the United States since 1979, and by 1994, polio was declared eradicated in all of the Americas (Maybury). The discovery and use of the polio vaccine significantly impacted the life expectancy and quality of life of Americans.