By the way, I know its hard to avoid illness if you have an older child that is out in the world in any way. We took my 1 year old to a play date when I was pregnant and he got so sick and then I got so sick. But I couldn't lock my son up . . . so it was what it was. So, I understand how hard it is!
Well, that is too bad. I'm sorry to hear this. The usual way to ward off colds is to wash and wash---- wash hands, clothes, touch as few things as possible, avoid sick people, avoid crowded places, etc. Does your doctor tell you why your immune system is so down?