Dreamless sleep did seem like the best solution, but Percy was right: there was no way they could medicate everyone forever. New supplies only came in once a month and they would run out long before then.
"I guess the place to start," she said slowly, mostly thinking aloud, "would be to talk to the people this happened to. To see if they can get it twice. There's this Muggle disease little kids get called the chicken flu, and if you get it once, you don't get it again." Maybe they'd be lucky and a lot of people would be immune now.