Untitled Part 1

The Scientists created a serum that makes subjects faster, stronger, heightens all of their senses. Most of The Trials have been successful. The serum was only tested on rats, moles, and horses. Soon, the Scientists became hungry for fame and injected human subjects. It seemed like some sort of Sci-Fi novel, a damaged society rising from the dead with actual super humans. Everyone rejoiced, happy that the human race was being mended of past mistakes.
At least, that's what everyone thought.
Now, half of the world's population is dead, cities decimated, and a plague running rapidly throughout the surviving human inhabitants of a broken world.
How will we survive this?