Earlier quoted context omitted.
Different species, you can't generalize like that. It's pretty unclear what actually happened with H1N1. Scientists were able to resurrect the more virulent strain in the lab two decades ago and it was just as potent in lab animals... Two possibilities are that it did in fact mutate to become "milder" or those strains were already circulating. Either way, H1N1 killed so quickly it ran out of victims and the highly le…
I was under the impression that it mostly killed by causing cytokine storms.
After reading this, I am less sure of the claim "most", but it seems that opportunistic infection was an important factor. There were a few unpleasant ways to die...