Polio had been a scourge killing and maiming children for centuries. The process for developing a vaccine for a virus was straightforward: a weakened or dead form of the virus and injected into the body. The body’s immune system responds by building up recognition of the foreign invader and if it sees the invader again it is prepared to rapidly extinguish it. The challenge that Johnson, Culbertson, and Eli Lilly were facing was how to get a large amount of weakened or dead polio virus to prepare a vaccine.
Three men, Thomas Weller, John Enders and Frederick Robbins figured out how to grow polio virus in laboratory strains of kidney cells. Previously, polio virus could only be grown in live rabbit brains. Jonas Salk understood the significance of this discovery. He reasoned that if you could grow the virus in kidney cells, then you should be able to grow massive amounts of the virus, treat it somehow to deactivate it, and use it as a vaccine. Eli Lilly did the work growing up polio virus, deactivating it, and packaging it into vaccines. Jonas Salk was the first to test whether this vaccine was safe and effective. Salk organized a large and controversial clinical trial involving over 1.4 million subjects that started in 1954. Irving Johnson was a key player at Eli Lilly in this project.
When Irving Johnson joined Lilly in the late 1950’s, he would occasionally see Clowes, the former director of research at Lilly, who struck the initial agreement with the University of Toronto about the manufacture of insulin. Clowes was retired, but Lilly gave him an emeritus position at the company.