Game Changer?

It is evident, to most people, that we really do need a quick and reliable test for blood antibodies to determine who has been exposed to the Covid-19 virus and consequently might be able (with documentation?) to safely return to work (especially in the NHS or care). It now appears, however, that the ordered test is not as reliable as had been hoped (https://www.theguardian.com/world/2020/apr/05/coronavirus-testing-kits-could-be-unreliable-uk-scientists-say). Although it had been claimed to be 90% accurate, this was only when tested in hospitals using blood from people with very clear systems. Some authorities feel that the test is likely to be only have a 50% accuracy (the same as tossing a coin!) in people in the community with milder symptoms. This could never be an acceptable basis for returning people to the 'front line'. I would personally be unhappy with people testing themselves (as they do with a pregnancy test) and self-certifying