Governments around the world are testing citizens for coronavirus antibodies, to work out whether people have had the deadly Covid-19 disease.
Some countries are setting up so-called "immunity passports" and others may follow suit.
The idea is that a passport would certify that you have had coronavirus and will not carry or contract the disease again, opening up a way out of lockdown restrictions for the holder.
But is this theory correct? And will it create a group of antibody-carrying elite who can date, travel and work as they wish, while others are still limited by health precautions?
