"D'ya think dat someone could be a hybrid of a human an' zombie...? Not a human matin' with a zombie, but, like, half-infected?"
There are a few things that you could be referring to here, actually!
The first is the most simple explanation, and it is simply that the extent of the physical mutations can vary wildly even between infected of the same “subset”, so there are certainly hosts that are less... er... visibly changed. These individuals are definitely still infected though and will behave as such.
The second is more likely, and would actually be a carrier, such as myself. The infection is passed on much as any disease, but somewhere around a quarter of the population is genetically immune. These people cannot turn, and cannot be infected. Their bodies will resist any incidence of the pathogen. Let’s call them “group A”.
“Group B” in this case would consist of both carriers and non-immunes/the infected themselves. So what is the difference between a carrier and an infected? It is, in fact, a singular, recessive gene, separate from what grants group A their immunity. A carrier is capable of becoming infected, and the disease may in fact remain active indefinitely. However, rather than not being infected, they lack the capability to turn. Functionally, other than that, they are indistinguishable. Every test for the green flu pathogen will turn up positive, and passing the disease on is entirely possible. Most carriers would have no idea, and assume that they were in fact immune until proven otherwise.
So essentially, they remain an ordinary human. No mutation, no behavioral alteration that we’ve been able to observe, anyways. And yet, at the same time, they are in fact infected. This may be the closest to simultaneously existing as an infected and an uninfected person at the same time.
