What about, instead of a cure, a vaccination? Can’t cure someone who is chopped in half (remember episode one) but a working vaccination would be a MAJOR power shift, especially if it is rare or hard to manufacture.
Nice! I like it! Or maybe the Guv turns into some kind of zombie-human half-breed!
At the end of season one, Dr. Jenner told Rick that they were all already infected. So, everyone will turn into a walker after they die. Being bitten or scratched by a walker seems to cause "walker fever" (my term) that kills people pretty quickly (maximum time seems to be a couple of days). So, whatever vaccination they might come up with has to deal with the fact that they are already infected.
A vaccination is protection against infection, everyone is already infected....But that's not an issue in this series.
The real issue is survival against the expected fallibility and ultimate collapse of civilization in a post apocalyptic world......And the actions and decisions its survivors are willing to make in order to survive.