Corruption (The Undead Possession Series Book III) by Justin Boote
After escaping the half-breeds, Chris and friends make it to a new shelter where they meet with fifteen others, and where Chris can continue creating an antidote. And soon, he has success. After capturing a half-breed and injecting him with the antidote, he recovers and is able to safely mingle with the others.
But other dangers are present.
Deeply religious Mark has visions. Is given a sign of what is to come and that he will have an important part to play in all this.
Because Sam knows where they are. She has had her child and can now proceed to complete the rest of her plan; turn the half-breeds into a super race of demon-zombies while tracking down Chris and co.
Can Chris make the antidote in time before she finds and captures them or will the full-breeds take over the rest of the country, and eventually the world?