Is a Zombie Apocalypse Possible?
Before we go into the details of whether or not we would be able to survive a zombie apocalypse, we need to first understand what it is. What sequence of events will lead to an event which can be considered as a zombie outbreak? Well there are various factors which must be fulfilled but the most important are:
1. There must be a highly contagious plague with the capability of killing people en-mass.
2. All or a subset of the people who are infected must be transformed into zombies.
3. The key carrier for this disease must be the zombies.
4. The plague must be so severe that it must threaten the existence of human beings and throw them to the brink of extinction.
Is it possible?
Now that we have clearly defined what a zombie apocalypse is, let us now find out whether there is any possibility for it to happen. In this day and age, the field of medical science has advanced to a great extent. However, there are still pathogens which have been resistant to the latest antibiotics and we are still unable to find the cure for many diseases. So it is viable that a newly mutated pathogen can come up. It is also possible that the new pathogen could be highly contagious and capable of spreading quickly with no cure in sight. This soon turns into a plague infecting billions of people.
What is a zombie?
Having infected a majority of the population, the pathogen must then be capable of mutating and producing zombies. So what do we consider to be a zombie? Normally a zombie would be considered as a person who was raised from the dead using necromancy. However, in this case, a zombie is just a person who is possessed by a pathogen, unable to think or act on his own and acting as a carrier for further spreading the disease. So technically a zombie would be an infected person who has completely lost his mind and senses. But he will still be considered as a "living person" who can even be cured by an antidote.
Real life zombies:
So can a pathogen really be capable of such a feat? Sadly it is more common than we expect. For example, there are many species of parasites like Hair-worms who infect insects such as crickets and take over their bodies. After having a free stay in the cricket's body they emit chemicals to control its body. The Hair-worms need an aquatic habitat to reproduce and so they make the crickets commit 'suicide' by jumping into a water body and drown after which the Hair-worms can emerge out. It is therefore quite likely that a pathogen can develop such a trait as well.
The start of the disease might not be that dramatic. If it were so, then it would raise an alarm and be quickly suppressed. So the pathogen will start off as a being harmless or a minor nuisance at best. It might masquerade as any other common illness such as a cold and thus avoid detection. With no major concern regarding the new disease, it will spread rapidly throughout the world. The pathogen will be capable of resisting hot and cold temperatures in order for it to survive in diverse conditions. It will also have an effective means of transmission. This can be either through the air, water or by carriers like animals, birds, and humans. With these characteristics, the pathogen has now made its way to a majority of the population but it is still not lethal.
The symptoms and true effects of the disease will start showing once it's all but too late. A plague alert will be in place. The pathogen will now mutate into a lethal killing machine. The worst part is that it does not just kill but causes its victims to become zombies. As we have seen earlier it is possible for the pathogen to take over the mind of its victim. It will not be fully in control but enough for the person to turn into one of the walking dead. Either the person is killed immediately by the disease or he is unfortunate enough to become a zombie first and die eventually. The zombies themselves help spread the disease even faster.
Characteristics of a zombie:
A zombie is a living person whose mind has been taken over by the pathogen. It is important to note that a dead person cannot become a zombie. If a zombie is killed or succumbs to the disease it cannot come back to life again. A zombie is a carrier of the pathogen and coming into contact with a zombie will spread the pathogen. A bite from a zombie is sure to infect a healthy person as that would be the easiest way to transmit the infection. The lifetime of a zombie will be very less as the infection will cause the person to die quickly and they will not be able to survive easily without having any decent nutrition or water. The behavior of the person will be somewhat similar to what would happen in a rabies infection. Confusion and hallucinations will cause the person to be erratic. The pathogen will also want to transfer itself onto a new host and thus seeking to infect other healthy people. The zombies will thus be very aggressive and violent.
Chaos and confusion:
With more than half of the population of the world dead or converted into zombies there is utter confusion. The government in almost all countries breaks down and there is total anarchy. The remaining survivors are hunted down by zombies and there is fear of infection everywhere. The people who have become zombies need to be killed but there is a moral issue with such a decision as these might be small children or people who were close to you. And the sheer number of the zombies might overpower cities. Since they do not feel the pain they are unstoppable and deadly. Losing a limb or two will not stop a zombie so a killing blow is essential. Since the pathogen can be transmitted by other sources as well, the risk of getting infected is very high.
Vaccine and Cure:
Finding a cure and vaccine should take the highest priority. All the resources available will be put into this effort. Every scientist in the world will be working day and night finding a way to prevent this plague from spreading. The scientists from around the world would have come up with some kind of vaccine and cure for the disease. With so much effort put into this research, it is highly likely that at least a vaccine would have been devised. The already infected people will be purged and the remaining survivors will have to be vaccinated. Without the vaccine, chances for survival will be very slim as the plague will now be rampant.
Weakness of zombies:
You may wonder if the zombies would be sitting idly while the scientists work overtime finding a cure. After all, the zombies would be strong as they have no pain inhibitions and are filled with disease-carrying flesh. However, the fact is that the zombies have many weaknesses which are inevitable:
1. The zombies may be in the millions but they will not be organized in their assaults. They will just be a mindless mob of crazy folks.
2. They also have a very short life span which could be just a few days or months before they die eventually.
3. They may be controlled by the pathogen but they will definitely not be capable of wielding any tools or weapons. They will not be able to think logically which will seriously inhibit their threat. A simple act as climbing a ladder will save your life.
This would be a challenge of survival for mankind. The remaining survivors need to find a way to eliminate the zombies and be vaccinated to prevent any infection. Assuming the vaccine has already been created, it is likely that most people would be vaccinated. As far as the zombies are concerned, the best way to deal with them would be to do nothing. Confronting them and attacking would be a huge risk as even though you are vaccinated, a direct bite might not save you. And since their count is in the millions, it would be a monumental effort to eradicate them all. So the survivors would most likely find a safe place and wait out the storm. They might find a safe haven in the form of an underground bunker, or a ship or even just a house that is properly walled and impenetrable by conventional methods.
Having a good stock of food and supplies will be important for survival. Being vaccinated from the infection would be absolutely necessary. Having a safe place which is inaccessible for the zombies will ensure that you need not have to worry about fighting all day. The zombies would then slowly die out and in a few days, there will be no zombies left. The infection will also die out without any carriers. The people can then emerge from hiding and begin their life afresh. Things will not be like before but this would certainly be better than being extinct.
There are many issues which will still cause problems. There will be so many decaying corpses on the streets which will cause sanitation issues. The manpower in the world will be severely depleted. The livestock may also have faced irreplaceable losses. It will take a huge amount of time and effort to get things up and running. But the people who survived will develop a strong resistance to the pathogen which will ensure that the same will not happen again anytime soon. Eventually, the humans will be able to rebuild back as they have always done. The black death wiped out 60 percent of the population of Europe during the 14th century but anything that doesn't kill us completely only makes us stronger. But let us hope that we never have to face such an ordeal.