We are at the height of the scandal right now and I guess Akin will recover from this blunder if he stays in the race (which I find the most likely scenario). Akin's favorability ratings are probably going to improve if he manages to lead a flawless campaign in the next weeks while McCaskill's numbers are unlikely to change much. So Akin still has a good chance to win this race.
What makes you think that he possess the ability to run such a campaign? When he was third in the polls and way back from Steelman, his entire campaign was essentially based around him getting headlines for making one stupid statement after another to bring attention to himself. Worse still, he didn't even really win the primary by any particular action that he took, but instead won it as a result of the actions taken by Steelman, Brunner and McCaskil.