PITTSBURGH (AP) _ The vaccine bears his name, but Jonas Salk had plenty of help in the victory over polio, and his legacy includes researchers bitterly disappointed that he denied them their share of the glory.
At a packed news conference on 50 years ago on April 12, Salk's former teacher and mentor at the University of Michigan, Dr. Thomas Francis, declared that the vaccine was ``safe, effective and potent.''
Francis had led crucial field tests of it using scientific methods that were uncommonly exquisite at that time. The vaccine was 70 percent effective against the main polio strain and 90 percent against two others, he reported.
That infuriated Salk, a diminutive, sharp-tongued man ``who felt compelled to insist that he had created nothing less than the perfect vaccine,'' Dr. Howard Markel wrote in an article in the April 7 New England Journal of Medicine. Markel is director of the University of Michigan's Center for the History of Medicine.
Salk then attacked Francis' findings and insisted his potion might have been 100 percent effective if the government hadn't insisted on adding an antiseptic to it. In his fury, he never mentioned all the work done by his colleagues at the University of Pittsburgh, who sat dumbfounded in the audience.
Nor did he credit Harvard researchers John Enders, Frederick Robbins and Thomas Weller, who enabled the vaccine to be mass-produced by finding a way to grow it in monkey kidney tissue.
``He wasn't very generous in acknowledging his co-workers, to put it in the most kind fashion,'' said Dr. Julius S. Youngner, who worked with Salk in Pittsburgh and is the only surviving scientist of the core research team. ``He made the world think that he had done it all by himself and made everyone else anonymous.''
Salk's demeanor embittered Youngner so much that he left the team in 1957 and told off Salk when Salk returned to Pittsburgh for a portrait unveiling in 1993.
While at Michigan during World War II, Salk and Francis had developed a killed-virus vaccine against influenza. In 1947, Salk was recruited by Pittsburgh to establish a virus research program.
He believed that a killed-virus vaccine could also be successful against polio, but most scientists supported a rival, Albert Sabin, who was pursuing a live-virus vaccine that could be given orally, said David M. Oshinsky, author of ``Polio: An American Story.''
The March of Dimes funded both, creating ``a very tense atmosphere,'' Oshinsky said.
In the end, both men were successful. Salk's vaccine carries no risk that the virus could mutate back into an infectious form; Sabin's, which came out seven years later, has been easier to use in developing countries.
The two were bitter enemies to their deaths _ Sabin in 1993, and Salk in 1995.
In his later years, Salk became even more flamboyant, abandoning his white lab coat for ascot ties and silk jogging suits, Oshinsky wrote. His marriage to a social worker fell apart and he remarried a French painter, telling a reporter that the couple had the same world view _ ``there is art and style in all we do.''
Salk's son, Dr. Peter Salk, an AIDS researcher, regrets the controversy over credit.
``There is no question, this was a collaborative effort'' involving the University of Pittsburgh, the March of Dimes and other researchers, he said.
``I just don't feel this was an effort on my father's part to capture the limelight or focus the attention on him,'' he said, adding that his father even balked at having the Salk Institute for Biological Studies in La Jolla, Calif., named after him.
As for that day 50 years ago, when his father behaved ungraciously in Michigan, Peter Salk said: ``I just feel terrible that that took place, and that not everybody was named.''