RE: Mutation
>Viruses mutate from species to species, and transfer from
>species to species. None of them are good to get infected by,
>since there is a time lag before effective vaccines and
>medications are determined and manufactured. Resistence to
>therapy is not uncommon.
Actually, viruses cannot transfer that easily, from one animal species to another animal species, or from an animal species to a human one and, vice versa. Bird Flu has existed for centuries, perhaps since the dawn of time, and it is thought that viruses are becoming more prevelant and deadlier in the current times (and thus, the current panic and real concern) because of the practice in the last 50 to 75 years of placing birds (most commonly, although not always, chickens) in large, enclosed environments, where their food and the birds themselves can come in easy contact with their own refuse and feces and where close quarters also can create an easy environment for viral transfer. This close quarters and confinement of birds is also taking place in proximity to large urban areas of human, which are themselves in crowded and less than ideal settings as far as sanitation and health, which is creating an environment where a more pathogenic and virulent form of a bird flu virus can be transferred, in whole or in part, to humans.
A cold is a virus, for example, and one that mutates easily, which is why taking antibiotics for colds is reckless and harmful, since there is no baterial agent to "kill." The fact that it mutates easily (as with flus) is why there is no "cure" and one can contract a viral cold or a viral flu year after year. However, as the newspapers always suggest, there are a number of easy steps which people can take during flu season and cold season, such as avoiding close proximity and washing ones hands, etc.
For those who are interested, although I do not recommend the web site in whole, there is a good and thorough discussion of viruses, their history, etc., to be found here: http://library.thinkquest.org/23054/basics/index.html