The vaccine against polio proves to be a success. A day of triumph for the developer of the vaccine. He arrives with the head of the National Foundation for infantile paralysis. Hundreds of reporters and scientists from all over the nation gather for the announcement. Peopley on hand are the who receive the first injections. This gigantic experiment is symbolic of the equally great foundation, both scientific and philanthropic, without which it could not have been conceived or executed. The entire world heralded the discovery, which is assuring an end to one of the most dreadful diseases. Susan that is in april, 1955 transit announcement of the successful polio vaccine. Elena conis, you suggest there are some cautionary notes when you look at the history of the polio vaccine better relative to today. What are the largest concerns . Elena it is a really good question. I think the history of polio has a lot of lessons. The history of a number of pandemic diseases have a lot for us to kee