Like the Spanish (1918) Flu, it is possible that in the most lethal forms, all three cause a cytokine storm and turn the body’s immune system against the body itself.
You reference a "cytokine storm".
There is some historical/anecdotal evidence that ingesting tea made from elderberries reduces the bodies' production of cytokines and thus reduces the fever period by about 2 days.
Have you ever heard this thoery?
I still have a bag of dried elderberries in my pantry. They are bitter, and kinda reminiscent of cranberries. I consider them part of my survival kit.