From body+soul Mag;

This tea will bolster your defenses by building your immune system.  In Chinese Medicine Astraglus has been used for years to increase resistance to illness.  Ginger helps keep your system warm, and lemon balm and peel are gentle antivirals. These herbs as safe but as always talk with your doctor.

2 TBSP dried astragalus
1 TBSP dried ginger or 3-4 round   slices of fresh ginger
1/8 TSP dried or fresh lemon peel
1 TBSP lemon balm
Honey to taste 

  1. Heat the astragalus, ginger, and lemon peel in a quart of water for 20 minutes covered.
  2. Turn off heat. Add the lemon balm; cover and steep for 20 minutes
  3. Strain and discard herbs

Add honey to taste per cup of hot tea. Keep remaining tea in the refrigerator for no more than 24 hours.