The World Health Organisation has warned governments not to use so-called “immunity passports” to allow people to return to work simply because they have antibodies for COVID-19.
Immunity passports are a proposed way of allowing countries to begin to lift their coronavirus lockdowns in a targeted manner and resume economic activity.
They would be issued to people who have already overcome a COVID-19 infection and test positive for antibodies to the virus, based on the assumption they are therefore immune.
But in an update to its guidance, the WHO warned there was “no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection”.
There are reports of dozens of reinfections of patients who had previously been diagnosed with the disease in East Asia, adding weight to the WHO’s concerns.
Immunity passports have been suggested by health ministers in the UK and Germany, and Chile has officially announced its intention to issue them to patients who have recovered from the virus.
In the UK, Health Secretary Matt Hancock suggested “something like an immunity certificate or a wristband” to help manage the lifting of social distancing restrictions but critics described the proposal as problematic.
The privileges which an immunity certification could bring might also introduce perverse incentives, such as some people trying to contract the virus on purpose.
People could try to sell their certificate to someone who is not immune, as it could bring significant privileges such as exempting them from lockdown restrictions.
One academic explained to Sky News that this would make it crucial to tie the test to the person who had taken it – but that setting up a reliable identity checking system for the whole population brought its own challenge.
In addition to questioning whether the presence of antibodies conferred immunity, the WHO warned that the rapidly developed tests needed to be checked for accuracy and reliability before being used.
Inaccurate tests could falsely label people who have antibodies as vulnerable to it, and vice versa, but also need to be able to distinguish between the virus causing COVID-19 and other coronaviruses, such as MERS and SARS.
The WHO said: “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,” its guidance added.