This first paper is exciting, because it’s about people working on a fishing boat, and being exposed to COVID-19.
No, they were not forced onto a boat and exposed to it.
They are just testing people going onto these boats, and when they all test negative, they embark. If an unfortunate person was incubating the virus, and still testing negative, they spread it, later.
That’s what happened on this boat, and over 80% of the crew got the virus. Think about that! The virus spreads fast in confined places.
The good news: 3 people had neutralizing antibodies going into the boat, and all three did not get the virus.
The paper says one limitation of the study is that they didn’t have thorough followup with the crew, so we don’t know how many got sick. (Insert criticism of US healthcare here.)
This second paper is a summary of a national survey of Spain after their first surge. It’s also a preprint. Here’s a summary.
And here’s the paper. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31483-5/fulltext