Leaving lockdown means understanding immune responses to the virus

OF THE VARIOUSSARSCVThe EconomistThe Economist Today ideas being touted to ease the world out of viral lockdown, one of the most striking is that of giving “immunity passports” to those who test positive for antibodies to -o-2, the virus that causes covid-19. These passes would let people move around and return to work—based on the assumption that possession of such antibodies prevents reinfection. This might sound like a reasonable assumption. It is, after all, true of many other infections. Assumptions, however, are not data. So on April 24th the World Health Organisation issued a briefing note on why immunity passports are not a good idea: “There is currently no evidence”, it said, “that people who have recovered from covid-19 and have antibodies are protected from a second infection.”