Everything you have posted is 100 percent correct. What I don’t understand is why healthier people’s immune systems overreact and people over 50 do not, for example. This is the mystery to me.
It is due to the cytokine storm. Which is explained here:
http://www.fluwikie.com/index.php?n=Science.PrimerCytokineStorm
Or here:
http://www.wisegeek.com/what-is-the-cytokine-storm.htm
Or there is more out there on the www.