Jonas Edward Salk was an American biologist and physician best known for the research and development of the first effective polio vaccine, the Salk vaccine.

During his life, Salk worked in New York, Michigan, Pittsburgh and California. In his later career, he devoted much energy toward the development of an AIDS vaccine.

While being interviewed by Edward R. Murrow on See It Now in 1955, Salk was asked: "Who owns the patent on this vaccine?" Surprised by the question's assumption of the requirement of a profit-motive for his creation, he responded: "There is no patent. Could you patent the sun?"

Salk was born in New York City to Russian-Jewish immigrant parents, Dora and Daniel B. Salk. He had two brothers, Lee and Herman Salk. Herman became a veterinarian, and Lee became a clinical psychologist. Jonas graduated from Townsend Harris High School and then went to the City College of New York, where he earned a B.Sc.. He received a medical degree from the School of Medicine at New York University in June 1939.

While in college he met his future wife, Donna Lindsay, whom he married on June 9, 1939. They had three children: Peter, Darrell, and Jonathan. In 1968, they divorced, and in 1970 Salk married Françoise Gilot, the former mistress of Pablo Picasso.

As a child, Salk did not show any interest in medicine or science in general. He says in an interview with the Academy of Achievement:

"As a child I was not interested in human anatomy. I was merely interested in things human, the human side of nature, if you like, and I continue to be interested in that. That's what motivates me. And in a way, it's the human dimension that has intrigued me."

His first desire was to become a lawyer and only due to his mother's persuasion (which included her telling him he wouldn’t be good at it), he changed from a pre-law student to a pre-med student. During his first year in medical school, he was offered the chance to do research and teach biochemistry. He recalls this experience in the previously mentioned interview: “At one point at the end of my first year of medical school, I received an opportunity to spend a year in research and teaching in biochemistry, which I did. And at the end of that year, I was told I could, if I wished, switch and get a Ph.D. in biochemistry but my preference was to stay with medicine. And I believe that this is all linked to my original ambition, or desire, which was to be of some help to humankind, so to speak, in a larger sense than just on a one-to-one basis.”

While attending the NYU School of Medicine, he heard two lectures that would change his life forever. Salk reflected on the lectures in 1990: “In the first lecture, we were told that it was possible to immunize against diphtheria and tetanus by the use of a chemically treated toxin [to kill it]... In the very next lecture, we were told that in order to immunize against a virus disease it was necessary to go through the experience of infection. It was not possible to kill the virus... The light went on at that point. I said that those two statements can’t possibly both be true. One has to be false.”

In 1938, while still in college, Salk began working with Dr. Thomas Francis, Jr. on an influenza vaccine. In 1941, Francis was appointed the head of the epidemiology department at the newly formed School of Public Health at the University of Michigan, and Salk, who in 1942 won a research fellowship, followed him. Together they worked to develop an influenza vaccine at the behest of the United States Army. Salk advanced to the position of assistant professor of epidemiology and continued his work on virology.

After medical school, Salk first worked as a staff physician at the Mount Sinai School of Medicine in New York City. Later, he worked for Dr. Francis's virus lab at the University of Michigan in Ann Arbor. In 1947, he moved to Pittsburgh, where he led the Virus Research lab at the University of Pittsburgh.

During the 1950s, Salk developed, tested, and refined the first successful polio vaccine, using inactive (dead) poliovirus cells that were injected into the body. In 1955 he began immunizations at Pittsburgh's Arsenal Elementary School in the Lawrenceville neighborhood and made international news as the man who beat polio.

In 1965, Salk struck out on his own, leaving the University of Pittsburgh and establishing the Salk Institute for Biological Studies in La Jolla, California, where the major focus of study was molecular biology and genetics. The first faculty included many distinguished members such as Jacob Bronowski and Francis Crick. Salk directed the institute until his retirement in 1985.

During Dr. Salk's last years, he co-founded The Immune Response Corporation with Kevin Kimberlin to search for a vaccine against AIDS, and patented a p24- vaccine as "Remune".