Today’s rabies prophylaxis is almost 100% effective at preventing human death from the bite of a rabid animal. How did people come to understand rabies, and then develop a vaccination for it?
Research:

Percy Fawcett, Manuscript 512, and a Lost City in the Amazon, Pt. 1
34:05

SYMHC Classics: Swill Milk
39:22

Behind the Scenes Minis: Mary, Beulah, Baby Alive
33:26