This was my fifth sci-fi novel. It's not really horror, but there certainly are zombies in it. Here's the longer synopsis of the story:

 

The end of the world began with a neither a bang nor a whimper, but with pain. March 23, 2033 was the day the Tibetan hemorrhagic fever virus jumped species.

 

Eighty-two percent of the human race—more than eight billion people—died within six months, screaming as necrotic tissues rotted on the bone. Of the eighteen percent of humanity that survived the pandemic, nearly all suffered through intense fever that resulted in damage to the higher brain functions. They didn’t die, but they also were no longer quite human. Instead, they became ravening feral hordes, forever hunting for living things to eat: snakes, dogs, people—it didn’t matter. As long as it had a heartbeat, the zombies—for want of a better term—pursued and ate it. However these zombies were not the mindless, shuffling, automatons of horror fiction. They were something else entirely. They were fast, cunning, hunted in packs, and could use simple tools.

 

The remaining eight-tenths of one percent of humanity—fewer than eight million individuals worldwide—were immune to the virus. However, with the collapse of all governments and military they stood little chance of surviving long-term against almost two billion zombies.

 

And then, fourteen months after the plague struck, a Drahtch invasion fleet arrived with more than twenty thousand armed ships, two million ground troops, and a half-million colonists.

 

Mankind doesn’t stand a chance.

 

Or does it?