'No evidence' you can't get Covid-19 twice, says WHO
The World Health Organization said on Saturday there was currently “no evidence” that people who have recovered from coronavirus are protected from a second infection – even if they now have antibodies against it.
In a statement, the UN health agency warned against issuing “immunity passports” or “risk-free certificates” to people who have been infected, saying the practice may actually increase the risk of spread as they may ignore standard advice.
It also warned that the accuracy and reliability of tests for antibodies to coronavirus were not certain.
“Inaccurate immunodiagnostic tests may falsely categorise people in two ways,” the WHO’s latest scientific brief said. “The first is that they may falsely label people who have been infected as negative, and the second is that people who have not been infected are falsely labelled as positive. Both errors have serious consequences and will affect control efforts.”
Chile said last week it would begin handing out “health passports” to people deemed to have recovered from the illness, Reuters reports. Once screened to determine if they have developed antibodies to make them immune to the virus, they could immediately rejoin the workforce.
But, the WHO said: “At this point in the pandemic, there is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an ‘immunity passport’ or ‘risk-free certificate’. People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice. The use of such certificates may therefore increase the risks of continued transmission.”