I think one of the big conundrums with this disease is why children don't seem to be affected very much. There's talk about this being an etiological factor in Kawasaki disease, but that seems unclear at the moment. It seems like a really interesting question why they're not infected, or when they get infections, why they don't seem to get really sick.
Is there any possibility that having had another coronavirus recently protects you from a different kind of coronavirus? We know that coronavirus is a fairly common cause of the simple cold. Is there any cross-protection from one form of coronavirus to another?