The G-Virus was the result of the prototype parasitic creature that would become the basis for the Nemesis project: the NE-α. This parasite, which showed an amazing vitality and resiliency, was transplanted into Lisa Trevor, where it disappeared shortly after taking up residence in her brain. Examining Lisa after this event revealed the beginnings of the G-Virus. This discovery deviated greatly from the established T-Virus research, prompting William Birkin to go to Umbrella headquarters and ask for permission to begin working on a G-Virus project, to which they agreed. This is what led to the building of the giant underground laboratory in Raccoon City and the beginnings of a new virus developed under the watchful eyes of William Birkin.

The chief difference between the G-Virus and the T-Virus is that the G-Virus creates evolutionary processes in its host that eventually lead to entirely new life forms. The T-Virus only causes mutations in a single generation of organisms, while the G-Virus can reproduce itself in the form of G Organisms. In other words, G cells ravaged by the virus go on to fundamentally change its host organism's body structure, while simultaneously feeding off that body. This is how those infected by it undergo such dramatic evolution. In addition, the G-Virus is even said to bring the dead back to life. All this leads to the inescapeable conclusion that the G-Virus is an invention of monumental importance and even more fearsome than the T-Virus.

However, this virus was never developed further, thanks to the egotistic nature of its creator, William Birkin. Thinking about going over to the American military, William was afraid that his research would be taken over by Spencer and he began planning a way to acquire everything for himself. Finding out about this, Umbrella sent a team of its special forces to recover the virus. The situation changed drastically when William injected himself with the virus rather than hand it over. William used his own body to demonstrate what he called "post-human evolution."

About The Creation Of The G-Virus Vaccine

Like the T-Virus, a vaccine also exists for the G-Virus. It's called Devil and it attacks the G cells at their most vulnerable rear defenses.

When someone is infected by the G-Virus, the embryo can take all the time it needs to fuse with its host body, as long as the body's immune system doesn't resist it. When this fusion is completed, the host body's cell structure is swapped out entirely for the virus's and the organism evolves completely into a G organism. Looking at this process from the opposite direction shows that the opportunity still remains to use G antibodies. As long as they're administered in the early stages of infection, there's plenty of time for the antibodies to do their job.

Devil requires a special method of production and the first step is to assemble a machine known as a Vam. First, place a cartridge for harvesting vaccine base into the Vam. Then activate the machine and collect the cartridge which should then contain a white vaccine base. After preparations for this vaccine base have been completed, place it in the vaccine creation machine in the P-4 level experiment room. Activate the creation program and the process will begin automatically. After 10 seconds, the process is complete and the vaccine is ready. However, because the completed vaccine is extremely suspectible to shock or sudden temperature changes, utmost care is required in its handling.