Obama just exited a cabinet meeting and gave a couple of quick remarks on the flu. I've attached his remarks beneath the fold, but in particular, I thought he offered a clear discussion of why this flu strain is different than the seasonal flu strains:

somebody asked, why is this different from other flus? We don't know for certain that this will end up being more severe than other seasonal flus that we have had. It's been noted I think before that you have over 36,000 die on average every year from seasonal flus; you've have 200,000 hospitalizations.

It may turn out that H1N1 runs its course like ordinary flus, in which case we will have prepared and we won't need all these preparations. The reason that people are concerned is -- the scientists are concerned -- is this is a new strain. So what happens is, is that Americans and people around the world have not built up immunity in the same way that they've built up immunity to the seasonal flus that we're accustomed to. Those seasonal flus may change, mutate slightly from year to year, but they're all roughly in the same band. When you have a new strain, then potentially our immune systems can't deal with it as effectively. And there are indications that in Mexico, at least, what you saw were relatively young, healthy people die from these -- from the H1N1, rather than people whose immune system is already compromised -- older individuals, very small infants, and so forth.

That last bit about immunity and age is a useful way of thinking about this. Our immune system is pretty capable of dealing with seasonal flus. The problem comes when someone's immune system is compromised: Then they have more trouble. Conversely, our immune systems have no understanding of how to deal with H1N1. That's why the deaths haven't been confined to the elderly. As of now, it's not clear our immune systems offer any defense at all.

An analogy that's been helpful for me is to think of your immune system like the tires on your car. Getting a seasonal flu is like driving on a slippery road. If your tires are sound, there's little problem. H1N1 is like driving off a cliff. Your tires are of no help at all. For now, it looks like the drop isn't very far, and most people are surviving. But if that changes, it's a real problem.

Related: The White House now has a Twitter account, and they're promising to offer flu updates. But truly 1337 twitterers know to subscribe to the CDC Emergency or CDC eHealth twitter accounts for the realy cutting edge in flu paranoia. And everyone should of course be following my twitter.