Viruses, in particular that gross Swine that's going around, take about 3 days to incubate (in your body) before you know you've come down with the dreaded flu. Drinking hot liquids, including coffee (!!!) can help wash the virus out of your mouth and down into your stomach where it can't grow due to the acids. Chicken soup, tea, or just hot water have the same effect. Not a coffee drinker, gargling with very salty warm water can also derail a virus. The other place a flu likes to incubate is your nose. Doing a nasal flush or even just swabbing your nostrils with rubbing alcohol can kill the virus before it takes you down.