My teacher Paul Bergner made these awesome videos about herbs and vitamin D to help combat and prevent influenza. Have you seen them???
My general recommendations for flu prevention are:
5000-10000 i.u vit D daily during winter
Take Elderberries, Astragalus, Reishi, Shitake Mushrooms every day- in teas, soups, elixirs, tinctures (capsules of mushroom extracts are acceptable).
Eat warm nutrient rich foods – bone broth, vegetables, greens, clean, organic and free range meats.
Ensure your diet is rich in foods containing Zinc, Vit. C, and Vit A.
Eliminate as much as possible sources of sugar (holidays are tough, but keep it in check and if you feel like you are coming down with something, cut out the cookies. asap.)
Sleep at least 8 hrs a night- more might be needed by some folks.