Greg Laden's Blog

No one directly involved in this thought or asserted that the H1N1 swine flu was especially serious. They simply did not know. Being a very deadly disease that would spread quickly and kill easily was a possibility. Being like the seasonal flu in severity and pattern of spread was a possibility. For days now, people have been leaning towards the latter, and now that is pretty much where everyone is. The swine flu H1N1 virus is at present acting a lot like a seasonal flu. It is not going away, it is not killing healthy people by turning their immune systems against them. It is just acting like a regular seasonal flu.

So right now, H1N1 swine flu is still spreading as expected. It will probably continue to do so, but the most likely pattern may eventually differ somewhat from the usual seasonal flu. According to Richard Besser, the acting head of the CDC, novel flu viruses that are not the regular seasonal flu often make a shaky first appearance and have a patchwork pattern of flaring up here and there and dying off here and there. If that pattern emerges in the present case, you can expect Swine H1N1 to act like a somewhat haphazard version of the seasonal flu over the next several months. You see, the flu does better in its seasonal pattern ... which is why selection typically moves novel flu viruses into a seasonal pattern. So while this flu is poking around in our population in the wrong season, there will be mixed reproductive results. We are watching an evolutionary event.

Which means that it is a deadly disease that should be taken as seriously as we take the seasonal flu. Or even better, maybe we should start taking both this flu and seasonal flu more seriously than usual. Not to panic, but to take seriously the fact that your kids should stay home from school ... and not be sent off to the mall! ... if they are sick, you should not be coughing into the hand with which you shake other people's hands, and so on.

You will recall that I mentioned earlier that the pattern for the 1918 flu was to show up in the spring and be like a seasonal flu for a while, and then it came back and killed 50 million people in a couple of successive waves over less than two years. When asked about this on NPR this morning, Dr. Besser simply said, speaking of the experts at CDC and elsewhere, "That is on all of our minds right now."

Besser pointed out that what happens in the Southern Hemisphere over the coming fall and winter (which is their flu season) will be important to watch. This is where we may (or may not) see this flu continuing on its evolutionary journey ... into oblivion, into infamy, or into mere typicality. Depending.

Go wash your hands. Right now, please.