The Science of Halloween: Zombies
It’s no secret that humans have a fascination with the undead, perhaps coming from our fascination with death itself. In fiction, it’s an awesome idea to play around with: an unstoppable virus sweeps across the Earth, turning ordinary people into mindless, cannibalistic monsters. All of us, at one point or another, have entertained thoughts of a Zombie Apocalypse plan—but could zombies actually exist?
Depending on how you define a zombie, human zombification could theoretically occur in many ways, including various parasites, pathogens, nanobots and neurotoxins—some of which can already infect and control brains.
But perhaps the most likely cause is the very origin of zombie legends: rabies. Rabies is a viral disease that infects the central nervous system, and the infected display all the telltale zombie symptoms: intense mindless aggression, muteness, fear of light, a compulsive need to bite… Pop culture just takes this idea and pushes it to the extreme.
Unlike fictional zombies who immediately reanimate upon infection, the rabies virus tends to incubate in its host body for weeks or even years before symptoms appear—then, they become hyperactive, disoriented, and aggressive. However, if the virus’s genetic code mutated or evolved, the incubation time could come rocketing down. And since most viruses naturally have high mutation rates in order to survive and get past new defenses, it’s entirely plausible that rabies might one day infect a person within a few hours.
But the virus would also need to be highly contagious in order to trigger a pandemic. At the moment, humans usually catch rabies after being bitten by an infected animal, and then the virus just stops because it has to be transmitted through body fluids such as saliva—but if it could spread through the air like influenza, then hello, apocalyse. However: rabies would have to borrow traits from other viruses to become airborne, and it’s pretty much unheard of that two unrelated viruses, like rabies and influenza, would hybridize, or even borrow traits, because they’re far too different.
So the development of a zombie virus is possible, but it would be incredibly difficult to do—and you might not end up with a virus that makes people zombies; you might just end up with a virus that makes people dead. Decide for yourselves whether this is amazing or terrible news.