new info indicates it is aerosolized. this is bad news.
so the cruise ship will give a great many clues as this proceeds. the majority should get it. if they don’t...find out why a person didn’t get it.
A lot of people simply have stronger immune systems than others. I don’t know that there’s a way to effectively study that, as opposed to what might be some genetic strength or weakness in some people with regard to this virus.
There was an article recently about the lung tissue of men, and Asian people in general (I can’t find a date for the source study, and it seems to be another pre-print on biorxiv.org):
https://theprepared.com/blog/new-study-suggests-2019-ncov-may-hit-men-asian-people-harder/
(I’m not a scientist.)