njgal, my kids get sick probably a couple times a year... flu or viral that lasts a couple of days. They are getting better with colds now. I've been giving them a kids multivitamin and vitamin C as recommended by their ped and it really does help. You could also help build their immunity by making sure they get enough fruits in their diet and that they get enough fresh air. I know that's hard in the cold weather so we tend to stay indoors more..but that's where all the germs are. We have an air purification system at home that helps a lot with allergies and circulating clean air. Also, getting kids to wash hands is a great help as well. Anothe rimprtant thing is getting a reasonable amount of sleep every night-- quality undisturbed sleep. My kids don't take naps anymore although I wish they did, but they sleep well through the night.