I am not an expert on this by any means, so use a boulder of salt.
These are just things I have gleaned by reading some of the studies,
a lot of study abstract, a number of press releases, and many news
stories, as well as already being familiar with cytokine storms.

The bird flu can attack anyone, BUT with these particular strains the
risk is not the influenza itself.  The big risk is that these strains
start a type of immune system over-response called a cytokine storm.
Cytokine storms are very dangerous, and can too often be fatal.  The
reason that most (not all) older people are safer is because more older
people have compromised immune systems.  The worst cytokine storms happen
in those with strong immune systems, so the young and strong are at
greater risk.

Yes, ferrets do get fatal cytokine storms with this influenza.  They
don't seem to catch it as easily as cats (including some of the big
cats) but ferrets approximate humans more closely in how their bodies
behave with influenza, and in this case also with cytokine storms.

Vaccines and anti-virals are not the approaches under study for reducing
or preventing cytokine storms.  There is some primary cytokine storm
research happening in the world, too.

I do not know what they are doing in terms of the vaccinated ferrets this
time.  Regular influenza vaccine ferrets have been adopted out afterward
by some companies, as have ones used for teaching premmie intubation by
some hospitals and teaching programs.  This is a more serious infection
type, though.  Normally, if a test animal has any chance of spreading a
disease which has too high a chance to be fatal the animal will be
destroyed, BUT I could imagine them wanting to watch longer term because
they also will want to document any possible vaccine problems, so the
ferrets might be kept alive longer term for observation, and that might
also remove any contagion concern after a certain period.

From what I have read the practice used to give the virus to the ferrets
has typically (?) been a trachea wash with live virus.

This particular influenza is one found deeper in the respiratory tract
than the usual, which is why the only *possible* human to human cases
have involved people providing intensive nursing to the sick ones.  It
is not so far being shed by things like sneezing because it settles deep
and tends to not be dislodged even by most coughing.  There are two
possible dangerous mutations researchers are looking for.  One would
allow it to live in the upper respiratory tracts which would allow
casual spread.  The other would allow it to replicate more effectively
in humans.

At this point it is figured that vaccine is not expected to be widely
available given the production needs, so humans in critical positions
will come first: medical and emergency personnel, police and
firefighters, etc.  I suspect we can be sure that the politicians will
figure they are up there, too.  There is also work going on, though, to
see if a generalized nasal vaccine approach can be used with virus that
is not grown in eggs.  If so, production will be faster and in higher
numbers.

Okay, just another note: yes, sick people WILL catch this, in fact that
is one of the big worries in areas with high rates of HIV and AIDS.  The
thing is that people with compromised immune systems get the illness but
not the immune system over-reaction (the cytokine storm), so they do not
die off rapidly with it.  But if a person's immune systems is hugely
compromised, as with AIDS, then the disease can be present longer term
than in most other people.  The longer it is present the longer it has
to have a chance of changing in ways that are more dangerous to humans
partly because viruses tend to snip and incorporate genetic material
from hosts.  If this disease takes off as a casual infection it has the
potential to kill off a large percentage of the world's youth.

Again, boulder of salt for what I write on this...
[Posted in FML issue 5278]