On April 24, 2020 the World Health Organisation released a Scientific Brief that warned “[t]here is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.” This comes just as antibody testing kicks off in the US and as some “governments have suggested that the detection of antibodies to the SARS-CoV-2…could serve as the basis for an “immunity passport” or “risk-free certificate” that would enable individuals to travel or to return to work assuming that they are protected against re-infection.”[1, 2, 3]
A few days before it was reprted that “Michael Ryan, executive director of the World Health Organization’s Emergencies Program was asked how long a recovered COVID-19 patient would have immunity, he said, “We do not have the answers to that — it’s an unknown,” and added, “We would expect that to be a reasonable period of protection, but it is very difficult to say with a new virus — we can only extrapolate from other coronaviruses, and even that data is quite limited.””