Okay, first off, there's the regular old flu, which we talk about and get vaccines for all the time. This flu doesn't often kill people these days, but when it does, it is usually the elderly, the very young, or those with compromised immune systems.
But now there is the threat of the bird-flu that has jumped species and is very dangerous. The scary thing about this bird-flu, is that it is similer to the flu of 1918, and that flu killed many young, otherwise healthy, people. In 1918, people would have the sniffles one day and be dead the next. There is an antiviral drug for it, but it has only been manufactured in small amounts and the concern is that it will take too long to make enough.
I wouldn't say I am worried, but I am concerned and attentive to the situation.