The simian 40 virus is a much scarier and relevant example IMO. Jumped species during the first polio vaccine, present in 70-85% of tumors in some studies and it's seldom talked about. Thalidomide is an example of isolating the wrong isotope that ostensibly, wasn't well understood at the time. EDIT: Another good vaccine example. https://www.bbc.com/future/article/20200918-the-fiasco-of-the-us-swine-flu-affair-of-1976