Have you tried the Brauers Children's Cold & Flu at all? I also give my kids a multi vitamin everday - not sure what ones are applicable for 12 months, there are some, just can't think of the name off the top of my head - yep, Pentavite - I think. I remember, DS had a constant cough from 4 months to about 10 months of age, it wasn't until we went to England on holiday for a month that it went.