Requires: Herbs (1 per 2 minutes, i.e. 25% of a Monastery Garden)
Provides: Resistance against Plague and sickness.
Notes: If Plague is set on Active, be sure to get the Sisters before you get to Noblemen. That way, sickness and plague is drastically lowered. You still need the Surgery though. (Edit: 100% resistance can be achieved nowadays, allowing you to ignore Surgeries)