On February 8th, 2010, an official comic portraying the events prior to Zombie Panic: Source drawn by Henital Gerpes was released. The comic has no dialogue, as that is left up to the reader to imagine. The comic focuses on Eugene, Marcus, Jessica, and Paul, with the setting in Town. The comic was created before the additions of Lea, Vanessa, and Pedro to the game, hence their absence.
Jessica notably is wearing her clothes from her original introduction to the game, rather than her current attire which came in an update later.