[mattmanser]

I also wonder how effective these anti body tests are, and their false negative rate.

In actual trials, has a single one actually been shown to work reliably?

Here in the UK there's a new story every week about how yet another antibody test has been withdrawn or rejected by PHE because it wasn't accurate.

[lbeltrame]

Most studies I've seen did their own validation because of this. Of course this doesn't mean the tests were accurate (or not).