This is a terribly generic question…
Okay, here is one: In the (now Legends) X-Wing Novels by Michael Stackpole, a central plot point is a genetically engineered virus. Simply “finding a cure with science” fails, thus they need Bacta to keep the sick alive. Problem is that the antagonist has taken Thyferra, the source of Bacta. Any word more would be a major spoiler.