Albert Wesker, father of Jake Muller, had a very rare physiology. His body was highly resistant to viral infection, and he was even able to manipulate the virus he had injected into himself so that he would only reap their benefits and none of its deleterious effects. This self-experimentation gave him abilities that can only be described as superhuman.

As Albert's son, Jake enjoys the same immunity to viral infection. When Jake injects himself with a solution containing the C-Virus, it has no visible effect on him.

- Jake Muller's Infamous Father