the second time you catch it is worse since you don't build up an immunity to it really makes you think.

Yes this part is a bit crazy... I've not heard of a disease doing something like that before.

Also the twist about it focusing on the ACE2 receptors, which are more commonly present in the lungs of males, and in Asians.

This disease has all sorts of odd characteristics. I do kind of wonder if someone planted it there from outside of China. Like imagine if the US or someone sold China this bioweapon, and then a few months later caused an outbreak next to the facility with the same bioweapon. China wouldn't know if they did it or someone else did. And the blame can fall neatly on China, with few suspecting anyone outside China as being the cause. Just a theory, but it does make a few part of the story make more sense. It's just as possible it was a genuine leak too though, who knows.