"Besides replicating very quickly, the 1918 strain seems to trigger a particularly intense response from the immune system, including a ‘cytokine storm’ – the rapid release of immune cells and inflammatory molecules.
Although a robust immune response should help us fight infection, an over-reaction of this kind can overload the body, leading to severe inflammation and a build-up of fluid in the lungs that could increase the chance of secondary infections.
The cytokine storm might help to explain why young, healthy adults – who normally find it easier to shake off flu – were the worst affected, since in this case their stronger immune systems created an even more severe cytokine storm."
BBC, Why the Flu of 1918 Was So Deadly
"Why is my language not clear to you? Because you are unable to hear what I say. You belong to your father, the devil, and you want to carry out your father’s desires. He was a murderer from the beginning, not holding to the truth, for there is no truth in him. When he lies, he speaks his native language, for he is a liar and the father of lies."
John 8:43-44