cannot keep sick toddler away from newborn

I have a sick toddler with a cold that's been well over a week and it's still as bad. my newborn is 5 days old. I've tried and tried to keep him away from her but I'm having a hard time he wants to touch her and keeps touching her bed etc. I've sprayed Lysol so much and try and make him sanitize his hands but I don't know what else to do. and i feel terrible hollering at him everytime he gets around her, but he won't listen. How bad is it for a newborn to get a cold? I am so worried.