7.) Rage virus
Featured in: 28 Days Later, 28 Weeks Later
Source: Wacky Animal Testing Experiments
Effects: Getting really, super angry

In 28 Days Later, a group of scientists decide to expose chimps to all of the hatred, malice and ill will in the world in order to condense human rage into a tangible, transmissible virus. For some reason. Of course, the Rage virus spreads throughout Britain quickly, effectively turning the majority of the population into a mass of howling, pissed off maniacs within a month.

Worse than Pig Flu?: The infected became so preoccupied with running around and tearing people apart that they forgot to eat, and eventually starved to death. Modest estimates suggest that the virus was contained to Great Britain with a second outbreak spreading to Europe, meaning that Swine Flu has some work to do if it wants to catch up. Judging by the formula, something bad will happen 28 months after first infection.