What I think the reason why Maeda is like the perfect host for the infected is probably he has a will power that the zombies don't have. He was already infected but he was able to redeem himself multiple times. Or in scientific explanation, he probably immune or he probably has antibodies that the zombies can detect. In the whole manga the zombies are rather called monster so I don't really think they are zombies like the plot description or it is just the mangaka's own interpretation of zombie.
What I think the reason why Maeda is like the perfect host for the infected is probably he has a will power that the zombies don't have. He was already infected but he was able to redeem himself multiple times. Or in scientific explanation, he probably immune or he probably has antibodies that the zombies can detect. In the whole manga the zombies are rather called monster so I don't really think they are zombies like the plot description or it is just the mangaka's own interpretation of zombie.