In the zombie flicks 28 Days Later and I Am Legend, an unstoppable viral plague sweeps across humanity, transforming people into mindless monsters with cannibalistic tendencies.

Though dead humans can't come back to life, certain viruses can induce such aggressive, zombie-like behavior, scientists say in the new National Geographic Channel documentary The Truth Behind Zombies, premiering Saturday at 10 p.m. ET/PT. (National Geographic News is part of the National Geographic Society, which part-owns the National Geographic Channel.)

For instance, rabies—a viral disease that infects the central nervous system—can drive people to be violently mad, according to Samita Andreansky, a virologist at the University of Miami's Miller School of Medicine in Florida who also appears in the documentary.

Combine rabies with the ability of a flu virus to spread quickly through the air, and you might have the makings of a zombie apocalypse...

... A faster mode of transmission would be through the air, which is how the influenza virus spreads.

"All rabies has to do is go airborne, and you have the rage virus" like in 28 Days Later, Max Mogk, head of the Zombie Research Society, says in the documentary. The international nonprofit is devoted to "raising the level of zombie scholarship in the Arts and Sciences," according to their website.

It's a safe bet that it's already been created, in weaponized spades.  To read the rest of the article, click here.