Meanwhile, the children aspect is still unknown, with what seems like two competing theories, as per this Wired article:
https://www.wired.com/story/kids-can-get-covid-19-they-just-dont-get-that-sick/
Specifically, these options:
Option 1 seems the lest likely to me. Like everywhere, China has high susceptibility to hayfever, and Wuhan has a rate of . Add to that, the fact that cities in China have horribly polluted air, and I think if option 1 were correct, we'd be seeing plenty of very sick kids, and we are not.
Option 2 makes more sense - in winter, there isn't a minute where kids aren't coughing, sneezing and blowing their noses in class, and colds sweep through schools. Maybe kids are somehow parlaying their constant exposure of mild coronaviruses in the fight against Covid-19?
That would also explain part of the reason why the very old are more susceptible - kids are potentially kept away from granny when they have a cold, so their exposure is much less.
I also wonder if vitamin D is a factor, because it just doesn't seem to be as catching in the summer countries as the winter ones, and kids obviously spend more time in the sun in general terms.