Not quite 50 years after the Salk vaccine was created, polio in America is a terror of the past. But in the '50s, tens of thousands of people -- mostly children -- fell victim to the disease every year. Come summer, when polio hit hardest, newscasts carried the day's tally of new cases. Parents were afraid to let children swim in public pools or go to the movies.
No wonder Dr. Jonas Salk, developer of the first polio vaccine, became a revered name. While the science that laid the foundation for the vaccine was done by others, it was Salk who moved with lightning speed to develop and test it. As he relentlessly perfected the vaccine, he had to face down critics who argued that his approach, which used an inactivated rather than weakened form of the virus, was flawed. "Taking a live infectious agent and rendering it into a safe vaccine was just a tremendous piece of work," says Emilio A. Emini of the International AIDS Vaccine Initiative.
Salk was born in New York in 1914. His strong-willed mother, a Russian Jewish immigrant, expected great things of her firstborn. After graduating from the City College of New York, he earned a medical degree from New York University in 1939 and went to work for noted virologist Thomas Francis Jr. at the University of Michigan. Under Francis, who was developing a flu vaccine for the Army, Salk showed a flair for laboratory innovation.
Salk had a restless ambition, however, and in 1947 moved on to the University of Pittsburgh. It was considered a scientific backwater, but he saw the chance to build his own lab. Funds were limited, so Salk took on the lucrative but tedious job of helping the National Foundation for Infantile Paralysis identify the strains of polio circulating in the U.S.
In 1949 the breakthrough that paved the way for the polio vaccine came when John F. Enders and his team were able to cultivate the polio virus in test tubes. Until then, scientists had to rely on infected monkeys for a supply of the virus. Salk seized on the discovery not only to accelerate his identification work but also to use in the next step: vaccine development.
Here Salk departed from many leaders in the field. Pioneers such as Alfred Sabin argued that true protection from the virus would come only through a vaccine based on a live, but weakened, virus. Salk and others said an inactivated, or "killed," virus could offer immunity. Dismissing critics, Salk came up with an effective way of inactivating the virus and personally conducted early human trials of the vaccine, which demonstrated its effectiveness.
But if Salk won long-lasting public gratitude after it was announced on Apr. 12, 1955, that the vaccine worked, he struggled to gain respect from his colleagues. Critics sniped that while his work was solid laboratory chemistry, others were responsible for the brilliant advances that made it possible. And some resented the sudden prominence that made him a figure much in demand. "My father wanted to go back to the lab," says son Dr. Darrell Salk, "but he couldn't."
Salk went on to found the highly regarded Salk Institute for Biological Studies in 1963, and in the years before his death in 1995, he was immersed in the hunt for an AIDS vaccine. Until the end he remained driven by the desire to turn scientific insight into real-world treatments.
By Amy Barrett