This is rank speculation, but I’ve wondered if these over-reactions in the immune systems of elderly people might be partly triggered by the fact that they are the people who’ve probably had the most flu shots in their lives, and their systems might therefore overreact because they’ve been loaded with too many antibodies. (I’m prepared to be told that this theory is bunk.)
That doesn’t really make any sense. Memory B-cells produce antibodies. They’re only activated by matching T-cells. Outside of activation by specific T-cells, they lie dormant because it uses a ton of energy to produce antibodies. If they were all suddenly activated, your body would die, but not for the same reasons as we see in cytokine storms, which are caused by a flood of pro-inflammatory triggers. Rather, you’d see multiple organ failure more similar to what you see in metastasized cancer. It would take a lot longer to do fatal damage, and that damage would be non-specific. In essence, you would die of exhaustion and a sort of malnutrition.
This is very different from the deaths we’re talking about.