Can 'immunity passports' help us get back to normal?

Countries around the world are working on ways for people to safely get back to normal, people like Pam in Scotland, who is navigating the world of app dating during coronavirus and wondering when, and if, to meet up. One answer is the idea of an immunity passport or certificate: something that shows you have had coronavirus and are now immune. Franz Walt, chief executive of Swiss firm Quotient, says antibody testing is so accurate it could be the basis for such a system. But Professor Robert West at University College London, says we don’t know enough about the illness to guarantee a passport system would work. And Stanford University historian Kathryn Olivarius explains how a 19th century yellow fever outbreak in New Orleans can help us think about it. (Picture: a testing vial. Picture credit: Getty Images.)