The team creates a model of the virus causing an epidemic to better understand how it behaves and affects human cells. The novel virus changes continually, so it is difficult for them to create a vaccine.
Johnny's sisters, Susan and Mary, create a chip that can be inserted into the brain to allow an individual to be connected to the internet at all times. However, that means the individual is exposed to computer threats such as viruses, pop-ups, and spyware. When The General implants the chip, which contains a virus, the virus takes over and makes him arms nuclear missiles. It is up to Johnny to defeat the virus and save the world from destruction.
Beakman explains what a vaccine is by acting like Edward Jenner. He explains how Jenner created the first vaccine using cow pox. Then Beakman uses a large ball (cell) with holes in it (receptors) and explains how viruses (a cube with pegs on it) attack our cells by attaching to the cell (pegs on virus go in holes aka receptors on cell). Beakman likens antibodies to cowboys ready to fight and explains how the immune system is normally triggered from a virus, unless that virus is too fast, then the body can't catch up. He then explains that vaccines work tricking the immune system into going ahead and making antibodies so that when you really do get sick, you can put up a better fight.
Thrax holds an evil meeting in which he highlights his successes as a viruses. He illustrates that viruses can cause sickness and even be lethal. Jones, the white blood cell, asks if there is anything he can do to stop the virus, indicating that white blood cells (also known as leukocytes) protect the body from illness, disease, bacteria, and other foreign invaders.