For those who don't want to bother; monkeys were infected with polio, killed, and their spines ground up to make the first batches of the vaccine. Aside from being infected with polio and euthanized, there didn't seem to be any effort to make the monkeys suffer more than necessary. This is a false equivalence.
Sounds more like an alchemical procedure than what I would've expected from "modern Western science", tbh.