There are many foods out there that can help boost the imune system due to their ingredients, a healthy diet will help prevent you from getting ill.
If somone said to me "Oh did you know, oranges are said to help cure colds", i would probably think they were talking a load of rubbish at first, but we all know that the vitamin C and natural sugar content in oranges can help boost our imune system and desease fighting capabilitys by helping us produce more white blood cells and stuff.
Initially i felt quite sceptical about kimchi helping cure bird flu, but then again you have to remember that bird flu is just another virus like to common cold, so i think its quite plausable that it could have the ability to help cure bird flu in certain cases like oranges can help cure a cold- who knows, maybe people will start to drop their macdonalds and KFC take aways and start eating healthier due to all this bird flu hype :? ? I guess at least bird flu won't entirely effect the local economys in certain negative respects/ways all the time.