I'm really not used to getting the flu or even colds. I attribute that mainly to the wonder plant that is Elder. When I was at university, I was sick quite often until I started consuming elderberry tea or syrup. I'm no medical professional, but this stuff really works. I went from almost always having a cold to almost never having one!
I love making my own blend of teas and often use my own herbs from the garden. Below is my favorite elderberry tea recipe. Elderberries can be a little difficult to find, but Mountain Rose Herbs sells some good ones online. I've bought them in health-food stores as well, but be warned that some have a bit of an after taste. You can use either catmint or peppermint for the tea. I like catmint for it's soothing properties, but peppermint is better if you are congested and may be easier to find in stores.
1 Teaspoon of (dried) Elderberries
1 Teaspoon of Catmint or Peppermint
1/2 Teaspoon Rosehips
1/2 Teaspoon Elderflowers (optional)
Combine the herbs and brew as you would loose tea. Steep at least 15 minutes for maximum effect.