I sent this link to Robb a few weeks ago and thought it was important enough to post. Paul Bergner (my favorite herbalist/vitalist) sent this out advocating the use of vitamin D as an immunomodulator because it specifically prevents the overexpression of inflammatory cytokines.
This is particularly significant because the theory behind severe epidemic flu (like in the 1918 Spanish flu and possibly H5N1) is the "cytokine storm" which you can read all about online. It's a bit less scary when you know the remedy.
My favorite flavor of CLO is Green Pasture's "cinnamon tingle."