"I hear kimchi is fairly effective too."
No, Kimchi keeps you from getting the flu in the first place. It works by the strong odor that Kimchi consumers have coming out their pores driving people away, so you don't have the opportunity to be around people, and you don't get exposed to what they have.
I understand that lonliness is a side effect of Kimchi.
Actually, it wasn't a joke as I normally would have made (though I agree that it probably can help you NOT catch the flu too with the smell--it took me 8 months to even acquire a tast for it), I remember some article saying something about kimchi having some kind of effect against bird flu. Can't remember where though. Korea hasn't had the problems yet that some Asian nations have, but it may be just a matter of time too.