My son is 14 and for the last year, even in the summer, seems to have a cold every month. These have on some occasions turned into chest infections.
He has older siblings and I have never had this with any of them.
Last year he was also diagnosed with Asthma.
He is a CF carrier of one of the rarer mutations, but I thought this didn't cause any issues.
He eats healthily and sleeps well.