1) Nobody knows yet how long the antibodies might last. A year might be bit of a stretch though.
https://www.bbc.co.uk/news/health-55651518
2) Yes, plenty. At least in the UK. Google will help.
My wife and I think it's possible we both had the virus a year ago before it became widely reported.
1. Can such a test detect antigens/antibodies after one year?
2. Are there any such tests commercially available?
1) Nobody knows yet how long the antibodies might last. A year might be bit of a stretch though.
https://www.bbc.co.uk/news/health-55651518
2) Yes, plenty. At least in the UK. Google will help.
It is a pointless exercise, because:
1) It is not clear if such tests can pick up the antibodies after such a lengthy period.
2) You may have had an asymptomatic infection in the intervening period which causes you to return a positive result.
3) All you will be able to determine from a positive result is that you had an infection at an unspecified point in time.
4) A negative result doesn’t mean you haven’t had an infection. Either the test might not be able to detect antibodies and/or the length of time since infection means there are so little circulating that they can’t be detected.
I would genuinely not bother taking this any further after a year!