Faz pelo menos alguns dias desde que o Herschel foi mordido. No final do S03E06, faz mais de um dia que Michonne entrou em contato com sangue infectado.
Até agora, não vimos nenhum caso de sobreviventes sendo infectados apenas por entrar em contato com sangue infectado. Eles só viraram após a morte.
Na verdade, em esta entrevista , criador Robert Kirkman confirma que o contato com o sangue não é suficiente para transformar uma pessoa. (ênfase minha):
This is a real Comic Book Guy question — but do I gather that if someone swallows a tiny bit of zombie blood they won’t turn into one of the undead? There was a lot of it being sprayed around this episode.
Yeah, people to a certain extent think of zombie blood as being like the blood from Alien. You know, in the Alien movies it’s like, “Oh god, if it touches you, you explode!” or whatever. Whatever it is that turns these people into zombies is in them already. So the idea of getting zombie blood on your face, which happens all the time, and it turning you into a zombie is something that’s just not the case.
Now, that doesn’t make the zombie bite any less lethal. You know, breaking the skin, having that kind of contact with the toxicity that zombie mouths would have, would be something that causes an infection that definitely would lead to your death and then the thing that’s already in you would turn you into a zombie. So there is a science to this, to a certain extent.