The show doesn't follow the comic exactly. The creator is heavily involved with both and has said he wants the show to be somewhat different so there are surprises for the fans of the comics who are watching. They're loosely following the arc in terms of Rick, Carl, and locations but not necessarily who lives and dies. For example, Andrea is one of the longest lasting survivors in the comics. But they killed here relatively soon in the tv show. Another change: Herschel is the one who gets bitten, captured, and eaten by Gareth's cannibal group in the comics. In the show, we had the Bob-b-q.