Swine flu spreads, and confusion with it

Updates from the flu front:

Confusion grows over the still-unreleased study
that apparently finds, contrary to other studies, that getting this
year's seasonal flu shot may raise your risk of getting swine flu. Peter Sandman, meanwhile, argues that since the swine flu seems
to have largely displaced the seasonal flu, getting vaccinated for the
latter doesn't make much sense. (I'm doing so this afternoon anyway.)

WaPo notes that the swine flu's second wave is starting to really make itself felt in the U.S., with over half the states reporting widespread flu activity.

Low stocks of Tamiflu (how long have we had to stock up?) seem to have contributed to the swine-flu death of an otherwise healthy 14-year-old girl on Sunday. Painful reading.

A timely Times article reminds us not to blame flu shots for every ailment that shows up afterwards. (Review correlation does not imply causation 101.) The CDC, meanwhile, will be doing its own close tracking of post-vaccination effects.

And Crof wonders whether it's too early to worry about the different hospitalization:death ratios in various countries.
One of his readers did a study that found the hospitalization fatality
rate (the percentage of those hospitalized who die) is 5.43% in Canada
but 9.42% in the U.S. (This is since the 'new' flu season officially
began on August 30, 2009.) Writes Crof,

I'm
hesitant to accept this ratio as a way of gaining an understanding of
H1N1. It may make me feel good as a Canadian to see that our public
health insurance may be saving lives while the uninsured Americans die
at almost twice our rate.

[He should included underinsured Americans in there too.] Then, after
outlining several caveats about such a study, he expresses feelings I
share:

Maybe
the hospitalization:death ratio is a useful tool in the hands of a
competent epidemiologist. Or not. I'd appreciate some advice from the
experts on this.

More like this

Has anyone posted an explanation of how the H1Ni flu would 'outcompete' seasonal flu? If there is no significant antigenic overlap, catching one flu shouldn't change your status as a potential host for the other. So why would an increase in new H1N1 flu reduce the opportunities for seasonal flu?