There's always a learning curve, where you've got to learn what your subject is all about.
In a series, you really need to stay open-minded. It's not like a play or a film, where you can create and fully commit to your character's back-story.
The idea of infection began to be taken far more seriously than it ever had before. Hospitals transformed themselves in response to the new plague - sometimes for the better, but often for the worse, as when, in fear, they cast their ulcerated patients out into the streets.