The World Health Organisation has raised alarm over the possibility of reinfection by Covid-19 of patients who have recovered, saying today that there was currently ‘no evidence’ that people cleared of the virus, who have the antibodies, are protected from a second virus infection.
In a scientific brief, the United Nations agency warned governments against issuing “immunity passports” or “risk-free certificates” to people who have been infected as their accuracy could not be guaranteed.
The practice could actually increase the risks of continued spread as people who have recovered may ignore advice about taking standard precautions against the virus, it said.
“Some governments have suggested that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, 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,” the WHO said.
“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection,” it noted.
Chile said last week it would begin handing out “health passports” to people deemed to have recovered from the illness.
Once screened to determine if they have developed antibodies to make them immune to the virus, they could immediately rejoin the workforce.
The issue was raised early this month in both China and South Korea, after several cases of patients who had tested positive, recovered and then reinfected.
The South Korean health authorities had referred to the possibility of initial fault in the diagnostic tests or the fact that the virus was dormant and had not cleared in the first place.
Scientists remain divided over the issue, which is reemerging as a real concern, more so following the WHO opinion expressed today.