The only documented evidence I can see of this is that between 1955 and 1963, there were some contaminants in the vaccines. The polio vaccine was to an extent that there's no way to track it was contaminated by some of the byproducts they were using to create the vaccine. Right. And it hypothetically could have caused some people to get cancer between 1955 and 1963.

It was not, from everything I can find, an intentional thing. It was what medicine was like in the 50s.