Eh, the philosophical implications of who to save or not could have gone much deeper.
On top of them being gone, if their bodies are rotted enough, would they still even be able to live without medical assistance if cured?
Or since it's been 6 months, who are left? Survivors that are actually good people or people that did horrible things just to be the ones who lived? Even if Romero dies to get a cure, what about a mutation to make it ineffective? What if there's no one left alive to be able to extract it anyway?
There's a lot of things to think about beyond nihilism or the needs of the many outweigh the needs of the few to talk about with the dynamic set up.
But that aside I still did this manga. XD