My 3 yr old daughter is quite healthy usually (although has a head cold as we speak!). She gets less than half of the colds that her non CAH brother does, and has only been on antibiotics about 6 times in her whole life; her dad is the same way - hardly ever getting sick, so I think that heredity probably plays a part. She HAS always been very well controlled, so perhaps there IS a correlation. It's frustrating when little ones keep getting sick; does your son go to daycare?? This seems to make a big difference, from what I've seen; I tryed to keep Annelise away from too many strangers when she was little - well, kept them from holding her or kissing her, at least! - and adopted a fanatic "Wash Your Hands!!" motto, but other than that, can offer no other suggestions. Hope this winter is kinder to all of you! God's blessings!