Just finished season 2
So the kid trashed the lab where they were trying to find a microbe able to kill the vampires. Then he opened the door and allowed his vampire mother to enter. And in the finale episode he was told by Nora to run. Instead he was just standing there, and when Nora was about to finish off the vampire, he shouted "no", distracting her and allowing the vampire tongue to infect her.
He should have been sent away a long time ago.