JONAS SALK AND ETHEL BAILEY IN THE LAB. ELSIE WARD IS VISIBLE IN THE BACKGROUND | JONAS SALK POLIO VACCINE COLLECTION, 1917-2005, UA.90.F89, UNIVERSITY ARCHIVES, ARCHIVES & SPECIAL COLLECTIONS, UNIVERSITY OF PITTSBURGH LIBRARY SYSTEM

On July 9, 1957, the polio vaccine developed by Pittsburgher Jonas Salk was declared safe and effective by scientists around the world at the Fourth International Poliomyelitis Conference in Geneva, Switzerland.

According to a New York Times report, “the widespread use of Salk anti-poliomyelitis vaccine throughout the world has confirmed studies in the United States of its safety and effectiveness.”

The vaccine was first administered by Salk in 1954. “Since then,” the Times reported, “100,000,000 doses have been distributed in the United States with safety, and reported complications following their administration have been remarkably rare.

“Scientists from other nations have reported similar experience [sic].”

The vaccine was shown to have approximately a 75% effective rate after one or two doses, but more research was needed as to the effectiveness of a full course of three doses worldwide, the report states.

Denmark, which had reached its goal of vaccinating nearly all of the population younger than 40, reported “only a few sporadic cases.” In the United States, they had achieved slightly more than half of their goal of immunizing everyone under 20 years old, but immunization of adults ages 20 to 40 had not been pushed to full force until the vaccine supply was more plentiful.

Last-scale immunization programs had yet to be taken in South America, the “Near East” and the Middle East, the report stated. “Soviet delegates to the conference” stated mass immunization efforts had begun in their country using the Salk technique scientists learned in a visit to the United States in 1955.

Salk became director of the Virus Research Laboratory at the University of Pittsburgh School of Medicine in 1947; it was there he began to develop a vaccine that could immunize against polio, which affected more than 40,000 people in the U.S. each year.

On April 12, 1955, the results of his testing were announced: the vaccine was safe and effective. By 1962, the number of polio cases had dropped to 910.

In 2019, Pittsburgh Magazine named him No. 5 on our list of the Greatest Pittsburghers of All Time.