Remember, it’s a two way street for mammals and viruses. We need each other to survive. Without one, the other would instantly disappear. As human population has significantly increased over the last 100 years viruses have been keeping pace. One other factor not discussed in this excellent diatribe is historical exposure to similar viruses. Some old people already have memory cell immunity that also assists “the herd” in reaching the same survival coverage. Viruses also know that and then they do their own mutating as a training tool. Don’t forget, as an example, we all have active Polio is in our gut biome. Someone/something is helping us out in keeping that modulated moderated. Is it viruses? Fungus? Bacteria? Parasites? A combo? Likely, yes. We’ll have to learn to roll with the punches......even if man screws around playing mix and match/gain of function. Consider it another straw on the backs of all mammals in an effort to continue forward.