Zombies are never quite explained. Except for the ‘resident evil’ franchise.
This whole idea started with the thought; what if the zombie ‘virus’ is actually a (man made) mutation of the vampire ‘virus’? (virus used very loosely. both conditions are traditionally some sort of blood transported infection)
Which is why I need the scientist. Governments were secretly aware of vampires. Under the ruse of finding a cure, they were looking into using some of the qualities of the vampire for military purposes. If only they could isolate and remove the bloodlust…and that went kind of wrong.