It’s been over a decade since Left 4 Dead 2 was released, and the game is still beloved by many. One of the things that makes it so special is the sense of mystery surrounding the infection that has turned most of the world’s population into zombies. What caused the infection? There are a few theories out there, and we’re going to explore them all.
Theory #1: The Green Flu
The most popular theory is that the infection was caused by the so-called "Green Flu." This theory is based on the fact that many of the symptoms of the infection resemble those of a real-life virus known as H1N1, or "swine flu." There are even some in-game references to the flu, such as a poster in one of the safe rooms that reads "Fight the Flu."
However, there are some problems with this theory. For one thing, the Green Flu doesn’t seem to be particularly contagious; it takes direct contact with infected bodily fluids to transmit the disease. Additionally, the virus doesn’t seem to kill its victims; instead, it simply turns them into zombies.
Theory #2: The Lazarus Virus
Another popular theory is that the infection was caused by the so-called "Lazarus Virus." This theory is based on the fact that the infection seems to resurrect its victims as zombies. The Lazarus Virus is a real-life virus that has been known to cause zombie-like symptoms in its victims, so this theory certainly has some merit.
However, there are some problems with this theory as well. For one thing, the Lazarus Virus is not known to be particularly contagious; it would be very unlikely for it to spread as quickly as the infection in Left 4 Dead 2 appears to have done. Additionally, the Lazarus Virus generally kills its victims, rather than turning them into zombies.
Theory #3: The Necroa Virus
The final theory is that the infection was caused by the so-called "Necroa Virus." This theory is based on the fact that the Necroa Virus is a real-life virus that causes its victims to become zombies. Additionally, the Necroa Virus is known to be highly contagious and to spread quickly through a population.
However, there are some problems with this theory as well. For one thing, the Necroa Virus generally kills its victims, rather than turning them into zombies. Additionally, the Necroa Virus is not known to be particularly virulent; it would be very unlikely for it to cause the global outbreak that is seen in Left 4 Dead 2.
Conclusion:
So, what caused the infection in Left 4 Dead 2? Unfortunately, we may never know for sure. However, the three most popular theories are the Green Flu, the Lazarus Virus, and the Necroa Virus. Each of these theories has some merit, but each also has some flaws. Ultimately, we may never know which of these theories is correct.