I noticed that there is Enchinacea ingredients in the Comvita. According to what I learned before (from books), Enchinacea cannot be taken for long run. The best result is to take Enchinacea when you first feel the symptom of cold, flu, etc. and continue to take it for several days (up to a week). If the product is pure Manuka Honey, you can take it for long run.
I live in Canada. I usually give my kids A. Vogel's Enchinaforce Junior when they have runny nose or flu. It helps them recover sooner. Also, oil of oregano (must have 75-85 Carvacrol) is good for flu and cough. But the taste is not easy for kids to take. These are natural food and are not medicine.