NEW YORK — Dr. Julius Youngner, an inventive virologist whose nearly fatal childhood illness destined him to become a medical researcher and a core member of the team that developed the Salk polio vaccine in 1955, died April 27 at his home in Pittsburgh. He was 96.
His death was confirmed by his son, Dr. Stuart Youngner.
Julius Youngner was the last surviving member of the original three-man research team assembled by Dr. Jonas Salk at the University of Pittsburgh to address the polio scourge, which peaked in the United States in the early 1950s when more than 50,000 children were struck by it in one year. Three other assistants later joined the group.
Salk credited his six aides with major roles in developing the polio vaccine, a landmark advance in modern medicine, which he announced on April 12, 1955.
The announcement — that the vaccine had proved up to 90 percent effective in tests on 440,000 youngsters in 44 states — was greeted with ringing church bells and openings of public swimming pools, which had been drained for fear of contagion. Within six years, annual cases of the paralyzing disease had declined from 14,000 to fewer than 1,000.
By 1979, polio had been virtually eliminated in developed nations.
“I think it’s absolutely fair to say that had it not been for Dr. Youngner, the polio vaccine would not have come into existence,” Salk’s son, Peter L. Salk, president of the Jonas Salk Legacy Foundation and a visiting professor at the University of Pittsburgh Graduate School of Public Health, said in an e-mail.
While Dr. Youngner, who was 34 at the time, remained at the university and made further advances in virology, he and other members of the team remained embittered that Salk had not singled them out for credit in his announcement speech.
The printed version was prefaced with the phrase: “From the Staff of the Virus Research Laboratory by Jonas E Salk, M.D.,” and a United Press account quoted him as crediting his original three assistants, who had joined him as early as 1949 — Dr. Youngner, Army Major Byron L. Bennett, and Dr. L. James Lewis — as well as three others.
“The really important thing to recognize is that the development of the polio vaccine at the University of Pittsburgh was a team effort,” Peter Salk wrote in his e-mail.
He added: “There is no question that my father recognized the importance of the team, and if there were circumstances in which that wasn’t adequately expressed, I would feel that it needs to be expressed now and very clearly so.”
In 1993, Dr. Youngner crossed paths with Salk for the first time since Salk had left for California in 1961. According to “Polio: An American Story” (2005), by David M. Oshinsky, Dr. Youngner raised the 1955 announcement speech in confronting Salk.
“Do you remember whom you mentioned and whom you left out?” the book quoted him as saying to Salk. “Do you realize how devastated we were at that moment and ever afterward when you persisted in making your co-workers invisible?”
Asked later, though, whether he regretted having worked for Salk, Dr. Youngner replied: “Absolutely not. You can’t imagine what a thrill that gave me. My only regret is that he disappointed me.”
‘I think it’s absolutely fair to say that had it not been for Dr. Youngner, the polio vaccine would not have come into existence.’
Dr. Youngner’s contribution to the team was threefold.
He developed a method called trypsinization, using monkey kidney cells to generate sufficient quantities of the virus for experiments and production of the vaccine. He also found a way to deactivate the virus without disrupting its ability to produce antibodies. And he created a color test to measure polio antibodies in the blood to determine whether the vaccine was working.
He later contributed research to understanding interferon as an antiviral agent in the treatment of cancer and hepatitis; to the development (with Dr. Samuel Salvin) of gamma interferon, which is used against certain infections; and to advances that resulted in vaccines for Type A influenza and (with Dr. Patricia Dowling) equine influenza.
“As a direct result of his efforts, there are countless numbers of people living longer and healthier lives,” Dr. Arthur S. Levine, the University of Pittsburgh’s senior vice chancellor for the health sciences and dean of its medical school, said in a statement.
Julius Stuart Youngner was born on Oct. 24, 1920, in Manhattan and raised in the Bronx, where he survived lobar pneumonia, a severe infection of the lungs. His father, Sidney Donheiser, was a businessman. His mother was Bertha Youngner. He took her name when his parents divorced.
After graduating from high school at 15, he earned a bachelor’s degree in English with a minor in biology from New York University in 1939 and a master’s and doctorate of science in microbiology from the University of Michigan.
His first wife, the former Tula Liakakis, died in 1963. Besides their son, Stuart, a psychiatry and bioethics professor at Case Western Reserve University in Cleveland, Dr. Youngner leaves his wife, the former Rina Balter; a daughter, Lisa, an artist, also from his first marriage; three grandchildren; and a half brother, Alan Donheiser.