There is NO antibody test currently available.
This was in an article on the guardian.... today
* Is there any way to know whether someone has had Covid-19 in the past?*
Dr William Hillmann: At this point, we don’t have a test to tell that. We are developing antibody tests to check for a prior infection, but those aren’t ready for clinical use yet. The only definitive way to know that you’ve had it is to get tested while you have it and to have that test be positive.
Full article here
www.theguardian.com/us-news/2020/apr/05/have-i-already-had-coronavirus-how-would-i-know
And here is a CNN article. Just 3 days ago. The headline? * FDA authorizes first coronavirus antibody test*
www.cnn.com/2020/04/02/health/fda-coronavirus-antibody-test-authorization/index.html
Even more compellingly... my best friend’s husband is an NHS consultant general surgeon. I text him to say that someone in a forum has said they have got an antibody test and does he know where I can buy.
His response? “They don’t have one and you can’t buy one”.