I posted last night on another thread (hi, artifarti!), about our latest illness, and hope the reaction from my MIL will help put things in perspective.
DS is 19mo, and never got ill when he was younger (apart from some wheezing when he was 6mo). He has been having colds notably since going to nursery. Just recently a cough turned into wheezing, and we were admitted to hospital so he could have nebulisers (medicine aerosolised with air from a giant canister) to open his lungs, and have his lungs listened to every few hours. His temperature went away fairly early, and when the wheezing subsided, he seemed to be feeling quite cheerful. Because of the fever and breathing problems, DS was swabbed for swine 'flu and was offered Tamiflu (we took it). Mind you, given that DS's temperature went away before the respitory problems, we can't really see how it can be swine 'flu.
However, MIL has been worrying about swine 'flu for months, convinced that every cough is swine 'flu, AND hates nurseries (she had a bad experience with DS2), so she seemed to take this as a chance to press us again to take DS out of nursery (though "only" for the winter), at least "until he is older and doesn't get ill any more."
I do feel sorry for MIL for her endless worries (as she gets worked up and loses sleep) and for DS, being ill. However, there is no way in hell I (and, thankfully, DH) think taking DS out of nursery will make him better in the long run.
My parents took me to Nigeria for a year when I was about 1, and I attribute my excellent immune system to the challenges it faced there . I really want the same for DS. The more they are exposed to now, the more adaptable and robust their immune systems will be. This has been proven again and again.
This is not to say we shouldn't observe our DCs' health and keep track of anything which appears to be becoming chronic (e.g. breathing difficulties, rashes, ear infections, etc.).
Get well soon, all!