I say let him die. He was foolish enough to charge into a horde of zombies, so he should suffer the consquences. Besides, you're looking to create a survival horror feel to the campaign, no? It's going to be very difficult to keep that feel if the PCs realize that they are "special" and will never die.

My vote: Bracken and Kata both get zombified. You can promote one of the city guards in the inn to PC status for Bracken's player, and Javasa can find a new animal companion later.