Jonas E. Salk, 80, the pioneering virologist whose development of the first safe and effective vaccine against infantile paralysis made him a national hero and his name a household word in the 1950s, died of heart failure yesterday at Green Hospital in La Jolla, Calif.

Salk's development of the polio vaccine was the culmination of years of research by scientists and physicians all over the world, and it made possible the fulfillment of one of the major priorities of American medicine: the elimination of infantile paralysis.

On April 12, 1955, the vaccine was licensed for general use by the secretary of health, education and welfare, only hours after a dramatic and long-awaited official pronouncement that it had been found to be a successful defense against polio in massive field tests the previous year. Those tests involved more than 1 million schoolchildren and were said to have been the biggest clinical experiment in the history of medicine.

The vaccine's efficacy was acclaimed in the media as one of the great breakthroughs in medical history, on a level with the discovery of penicillin and the smallpox vaccine. The polio vaccine was met with an immediate and extraordinary public outpouring of gratitude and affection. President Dwight D. Eisenhower invited Salk to the White House, where he received a presidential thank-you on behalf of millions of American parents and a special citation praising him as a "benefactor of mankind." Legislatures established medical scholarships in his honor, and cities named streets after him.

Within weeks, immunizations were begun in doctors' offices and clinics throughout the nation. In the next decade, the United States would see a drastic reduction in the incidence of polio, a disease that had scourged and terrorized cities and towns every summer since the early part of the century. Annual epidemics left thousands of children dead or crippled for life, causing a public hysteria that conjured up images of the medieval plagues. In 1952, the year of the first preliminary Salk vaccine tests, there were 57,626 reported cases of infantile paralysis in America, 3,300 of which were fatal. In 1962, there were 910.

In the 1950s, Salk was director of the Virus Research Laboratory at the University of Pittsburgh's School of Medicine. He had been working on a polio vaccine since the late 1940s. He had played a key role in identifying the three types of viruses that caused polio, a critical development because it established the agents that a successful polio vaccine would have to attack.

He developed a vaccine that produced antibodies powerful enough to kill the polio viruses in chimpanzees, and in the spring and summer of 1952, he tested the vaccine on 45 children and 27 staff members of the D.T. Watson Home for Crippled Children near Pittsburgh. It triggered production of antibodies powerful enough to kill the polio viruses in those tests, too, suggesting that the critical breakthrough in the war against polio had, in fact, been achieved.

A tough-minded and methodical scientist, Salk often spent 18 hours a day on his research, six or seven days a week. He worked on developing an influenza vaccine at the University of Michigan before accepting the appointment at the University of Pittsburgh in 1947. He was known both for a remarkable skill in putting to use the technical achievements of other scientists and as a medical maverick who did not hesitate to challenge prevailing scientific orthodoxy.

He also was a medical celebrity. The drive to develop a polio vaccine was the major medical story of its time, and Salk, as the physician who would bring the project to fruition, was reaping most of the publicity. His work was promoted skillfully and aggressively in the media by Basil O'Connor, the flamboyant president of the National Foundation for Infantile Paralysis, which through its March of Dimes campaign was the primary fund-raiser for polio research and the primary dispenser of research grants.

O'Connor was a former law partner of President Franklin D. Roosevelt, who in the early 1920s had suffered a crippling attack of polio. Roosevelt's election as president in 1932 created a widespread awareness of the ravages of infantile paralysis, and O'Connor was adept and creative in exploiting this fact to make eradication of the disease a national priority. He also was Salk's primary benefactor.

On March 26, 1953, less than a year after the first successful preliminary tests of the Salk vaccine, O'Connor arranged for Salk to tell the American people about his work. To a national audience on the CBS radio network, Salk described the 1952 tests, saying they "provide justification for optimism" and adding that although much work remained to be done, it appeared that development of a safe and effective polio vaccine was within sight.

The story was page-one news in newspapers all over the country the next day, further enhancing Salk's status as the primary player in the campaign to eliminate polio. As testing of the vaccine continued throughout 1953, his status as a celebrity continued to mount. At 40, he still had the appearance of youthfulness. With an attractive wife and three lively sons, he made good copy. He had grown up on the edge of poverty and risen to the top of his profession as a research scientist, but he had accumulated no wealth for himself. And he was delightfully bashful about the personal publicity he received.

To no avail, he protested use of the term "Salk vaccine," noting that the rabies vaccine was rarely called the Pasteur vaccine or the smallpox vaccine called the Jenner vaccine. But in an age of mass communications, "Salk vaccine" fit easily into headlines, and it was handy on radio and television.

It also stirred up a degree of resentment in the scientific community, where it was well known that without the years of research by hundreds of other scientists all over the world, Salk never could have developed his vaccine. One of the critical milestones in this process had been reached in 1949 at Harvard Medical School by John F. Enders and two colleagues. They discovered a way of cultivating, in a laboratory, large amounts of the polio viruses. For this they used kidneys that had been surgically removed from polio-infected monkeys. For their work, Enders and his associates would receive a Nobel Prize in 1954, an honor that eluded Salk.

"He threw a long forward pass, and I caught it," Salk would say later in interviews.

As preparations were going forth for the mass field tests of Salk's vaccine in 1954, O'Connor and the National Foundation for Infantile Paralysis decided to take a $9 million gamble. Should the vaccine prove effective, there would be an immediate demand for it. But the evaluation of the field tests would not be complete until April 1955, and this would be too late to produce and distribute the vaccine in time for that year's polio season. Betting on a favorable evaluation, O'Connor went ahead and bought $9 million worth of the Salk vaccine in 1954 for use the following year.

For the most part, that turned out to be a wise decision, although there were major problems. Some of the vaccine turned out to be defective, and there were sporadic instances of children contracting polio after receiving the Salk vaccine. Eventually, the defective vaccine was identified and withdrawn from the market.

By the end of 1955, 10 million U.S. children had received the vaccine. The polio figures for that year were 28,985 cases, 25 percent below the U.S. average for the previous five years. By 1956, 30 million Americans had received at least one inoculation of the Salk vaccine -- three were recommended -- and the polio figure was cut to 15,140, a reduction of 61 percent.

Within six years, Salk's vaccine had brought about a 95 percent reduction in the incidence of polio in the United States, preventing an estimated 300,000 cases of the disease.

But it also was becoming obsolete. In 1958 and 1959, extensive field tests were done on an oral vaccine developed by Albert Sabin. Unlike Salk's vaccine, the Sabin vaccine used a live virus -- the polio virus in the Salk vaccine had been killed -- and it seemed to offer immunity for longer than the Salk vaccine. It could be stored indefinitely in deep-freeze units, and it was inexpensive to produce. After 1962, it had almost entirely replaced the Salk vaccine.

Born in New York City, Jonas Salk attended City College of New York and received his medical degree at New York University's medical school. He did his internship at New York's Mount Sinai Hospital, and then in 1942 won a fellowship to do research on influenza viruses at the University of Michigan.

Working there with a former medical school professor, Thomas Francis, Salk helped develop commercial vaccines against influenza. He became an assistant professor of epidemiology at Michigan, and then in 1947 joined the staff at the University of Pittsburgh, which was expanding its virus research program. While continuing to do research on influenza viruses, he also began looking into polio viruses, with increasing support and encouragement from O'Connor and the March of Dimes.

He would remain closely associated with the March of Dimes throughout the period of his work on the polio vaccine and afterward. In 1963, he left the University of Pittsburgh to establish the Salk Center for Biological Studies in La Jolla. The center was supported financially by the March of Dimes. Its research focused on the prevention of birth defects and the development of drugs to fight other diseases, such as multiple sclerosis. Salk retired from the center in 1975 but continued to do research in retirement.

In 1939, Salk married Donna Lindsay, a former social service worker. They had three sons, Peter, Darrell and Jonathan. That marriage ended in divorce in 1968.

In 1970, he married Francoise Gilot, the former mistress of Pablo Picasso. CAPTION: Jonas Salk, right, administers his polio vaccine to a Philadelphia schoolboy during a field test in 1954. The government approved the vaccine in 1955. CAPTION: Salk's vaccine, approved in 1955, cut the U.S. incidence of polio by 95 percent in six years.