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.
I like to write sad songs. They're much easier to write and you get a lot more emotion into them. But people don't want to hear them as much. And radio definitely doesn't; they want that positive, uptempo thing.