A zombie outbreak is possible - an analysis of the possibility of the rabies virus mutating into something even worse.

Disclaimer: I'm not a medical professional. I have a lot of medical knowledge, especially concering virology, but still this article is just a speculation. I'm writing it mainly because I want to study game studies and create an apocalyptic game someday.

Rabies is one of the deadliest infectious diseases in the world, with a mortality rate close to 100%. This is mainly due to the fact that symptoms begin showing once the virus enters the body's most vital organ, responsible for basically every function in the human body - the brain. Because of this, the virus stops the brain from proper functioning, which results in lungs paralysis, which means the person cannot breathe. The virus causes dehydration as well - it increases the amount of saliva created by the salivary glands to maximise its spread, but causes hydrophobia as well. This virus most likely causes these symptoms because bites are the most common form of transmission. This virus is usually transmitted when a rabid animal bites a different mammal, including the human. The aggression is also caused by the virus - this virus really wants to spread. 

However, with protective measures like quarantine, vaccinations and euthanasia of affected animals the virus doesn't have much of a way to spread. In this article, I'll discuss what mutations would the virus have to experience to become a real life zombie outbreak. 

Before we begin, I'd like to look up some scientific information on the virus and what is a zombie defined as. We're going to use the most common source of information on the internet - WikiPedia. This article might be extended by watched documentaries and read books as well.

Rabies is a viral disease that causes encephalitis in humans and other mammals. It was historically referred to as hydrophobia ("fear of water") due to the symptom of panic when presented with liquids to drink. Early symptoms can include fever and abnormal sensations at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is virtually always death. The time period between contracting the disease and the start of symptoms is usually one to three months but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system. [WikiPedia]

I think that it's critical to describe what encephalitis is as well, since not everyone is so well educated in this area. This is usually only known by medical professionals, students and people with larger interests in medicine-related topics.

Encephalitis is inflammation of the brain. The severity can be variable with symptoms including reduction or alteration in consciousness, headache, fever, confusion, a stiff neck, and vomiting. Complications may include seizures, hallucinations, trouble speaking, memory problems, and problems with hearing. [WikiPedia]

One misconception is that encephalitis is a form of dementia. The difference is that encephalitis is caused by an inflammation, while a dementia is caused by the deterioration of brain tissue. 

Inflammation (from Latin: inflammatio) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin calor, dolor, rubor, tumor, and functio laesa). [WikiPedia]

Basically an inflammation is part of a response to an infection of the tissue. The harmful stimuli can be, but are not limited to: pathogens (viruses, bacteria, parasites), allergens (fur, pollen, food) or irritants (acids, soap).

So, in conclusion, rabies causes encephalitis, which is an inflammation (infection) of the brain. 

As the brain gets affected, there is always a risk of irrational behaviour, which pretty much relates to the concept of zombies.

A zombie (Haitian French: zombi, Haitian Creole: zonbi, Kikongo: zumbi) is a mythological undead corporeal revenant created through the reanimation of a corpse. In modern popular culture, zombies are most commonly found in horror and fantasy genre works. The term comes from Haitian folklore, in which a zombie is a dead body reanimated through various methods, most commonly magical practices in religions like Vodou. Modern media depictions of the reanimation of the dead often do not involve magic but rather science fictional methods such as carriers, fungi, radiation, mental diseases, vectors, pathogens, parasites, scientific accidents, etc.

In this case, the zombie is not necessarily a reanimated corpse, but rather someone whose self-control has died due to the disease, but the body still lives on muscular memory. The zombie virus would begin as a minor infection, like the common cold, maybe influenza. Then, the host would begin to act erratic, aggressive and would attack healthy individuals, since the virus tells the brain to spread the disease. Usually, in zombie-related fiction, zombie viruses spread through a bite, which is very similar to how rabies is transferred. Rabies can also be transferred by transferring blood from an infected individual to a healthy person, however due to modern medicine it is a very rare occurence. Also, humans usually still have some of their sanity left when infected which means that they will try to prevent the bite. However, a virus possesses a mutation skill. 

A zombie outbreak could occur if rabies developed transmissions that would not be easy to notice. You can't not realise you've been bitten by an aggressive individual or animal, but if rabies mutated to be airborne or waterborne, it would be much more dangerous. The infected would not realise they have it until symptoms show, which usually guarantees death. However, in the modern world, when an individual suspects they've been bitten by a rabid creature, they immediately head to the hospital and get the vaccine, which usually prevents the pathogen from entering the central nervous system. However, this is not always the case. While researching for this article, I found a YouTube comment when someone claims that a girl has died even though she got the rabies vaccine in time due to the fact the bite she received was very deep and the pathogen not only entered the flesh, but it immediately got in her bloodstream. However, this is a YouTube comment - there's always a chance that it is fake. 

However, if the virus was airborne or waterborne it wouldn't exactly be what we consider a zombie disease. That's why I think that it would be more accurate if the virus mutated an immunity to the vaccine. I'm not even sure if this is actually possible, but there's a possibility of a new strain developing. The new strain wouldn't disappear with a single injection of the vaccine and the scientists would be trying to find a cure for it. However, due to the aggression displayed by infected humans and animals would increase the number of infections drastically. Insane individuals could break into houses and bite healthy individuals. That wouldn't really leave the scientists a lot of time, which could potentially result in an extinction level event.

Nevertheless, this event isn't very likely to happen, but I still encourage all the readers to remain vigilant and not ignore civil threats and new contagious diseases. Our own ignorance could kill us all. Especially in these concerning times, with the global warming accelerating, a new strain of some disease or even an ancient microbe could emerge due to the ice caps melting. Due to the disease being frozen for thousands of years, modern humans won't have an immunity to it, which could potentially be lethal in consequences. Infections may seem to become less lethal over time, however this is because of the advances in curing them and a natural immunity caused by evolution over the years. 

However surrealistic this may sound, something can always happen. We didn't foresee COVID-19 either, so it's important to remain cautious, especially in a time like this. 

Stay safe, but not scared!!!