Taking Echinacea at the first sign of a sniffle often bolsters the system sufficiently to help the body fight the virus. I also recommend tincture or tablets of astragalus, a powerful Chinese herb known to improve immune function. Plus, try my potent ginger-garlic tea to fight off colds and flu. Simmer one teaspoon of grated ginger in one cup of water in a covered pot for five minutes. Strain; add one clove crushed garlic, one tablespoon fresh lemon juice, and one-quarter teaspoon cayenne powder. Sweeten with honey if desired.