The Avian influenza or bird flu virus can survive indefinitely when frozen and up to 100 days in hen houses. A few years back when this flu was prevalent in Asia, a farmer fed his chickens kimchi. The result was that his chickens did not get or spread the Avian flu while other chickens in the region did. Why? Scientists have studied this and found that these viruses can be eliminated by kimchi, sauerkraut, and Greek yogurt because they produce a bubbling bacteria that kills it. I found this information interesting. So there is a natural source that works against this flu, providing of course you can stand the taste of it or can stand the breath of the person next to you that has consumed it.