Jonas Salk


First Clinical Description


British physician Michael Underwood provides first clinical description of the disease.

First U.S. Polio Epidemic


The first major documented polio outbreak in the United States occurred in Rutland County, Vermont. Eighteen deaths and 132 cases of permanent paralysis were reported.

Poliovirus Identified


In Vienna, Karl Landsteiner, MD (1868-1943), and Erwin Popper, MD (1879-1955), announced that the infectious agent in polio was a virus.

Popper and Landsteiner deduced the viral nature of polio by carefully filtering preparations of spinal cord fluid from a person who had died of polio. The filters were known to trap bacteria. When Popper and Landsteiner injected the filtered preparations into monkeys, the monkeys developed polio. The researchers then concluded that an infectious particle smaller than bacteria caused the disease.

The Iron Lung


Philip Drinker, PhD , and Charles McKhann, MD , at Boston Children’s Hospital and Harvard published a paper describing successful use of an artificial respirator for patients suffering from paralytic polio.

Cultivation of Poliovirus in Monkey Kidney Tissue


At the University of Pittsburgh, Jonas Salk, MD, and his team developed a method of cultivating polio virus in monkey kidney tissue. The method would lead to the ability to produce large quantities of virus for vaccine.

Polio Vaccine Worldwide


A large, nationwide controlled field trial of the polio vaccine began under the direction of Dr. Thomas Francis.

Global Polio Eradication Initiative


At its annual meeting, the World Health Assembly voted to launch a global polio eradication initiative. At the time, polio was endemic in 125 countries. The initiative called for the eradication of the disease by the year 2000.

Polio Declared Eliminated from the Americas


On August 20, 1994, the Pan American Health Organization had reported that three years had passed since the last case of wild polio in the Americas. A three-year-old Peruvian boy, Luis Fermín, had the last registered case there.



inactivated polio vaccine replaces oral polio vaccince as recommended method of polio immunization in the United States.

$200M Pledged to Fight Polio


The Bill and Melinda Gates Foundation gave a $100 million grant to Rotary International to combat polio. Rotary International promised to match the grant over a three-year period, for a total of $200 million to be used in the global eradication campaign.