Your other child shouldnt be able to catch it again. If he's already had it, he is done with getting it.. hopefully for the rest of this year! Sorry your baby still isnt feeling well =/ no fun! But it will all be back to normal in a few days, im sure.. i had it last month and didnt feel all the way normal until ten days after it started =( so it can linger about..unfortunately even more for the little babies.