COVID-19 antibody testing and ‘immunity certification’
The significance of any given level of risk in a particular context is always a matter of judgement,
which depends on how different hazards and benefits, and their likelihood of occurring are
valued. Certification turns a judgement about risk into a binary value that is invested with political
significance (for example, a specific permission or exclusion).
Certification can function like a passport (for example, as a condition to be admitted to a country or a controlled space, or to waive entry quarantine requirements) or like a licence (for example, to permit someone to carry out a particular function, such as serving customers). To be valuable it must be resistant to fraud by reliably encoding authentic information (for example, a test result) and linking that information securely to an identifiable individual (the person who was tested). Different forms of certification have been proposed in the context of COVID-19, including personal smartphone apps that encode or securely exchange relevant data, wristbands that combine location and health tracking but could also be set to signal risk status, and identity verification systems linked to a centralised database of test results and relevant information.