Q: Now, you worked in labs. Where purity was an issue.

A: The public believes that these labs, these manufacturing facilities are
the cleanest places in the world. That is not true. Contamination occurs
all the time. You get all sorts of debris introduced into vaccines.

Q: For example, the SV40 monkey virus slips into the polio vaccine.

A: Well yes, that happened. But that's not what I mean. The SV40 got
into the polio vaccine because the vaccine was made by using monkey kidneys.
But I'm talking about something else. The actual lab conditions. The
mistakes. The careless errors. SV40, which was later found in cancer
tumors -- that was what I would call a structural problem. It was an
accepted part of the manufacturing process. If you use monkey kidneys, you
open the door to germs which you don't know are in those kidneys.