The World Health Organisation (WHO), has stated that there is not enough evidence about the effectiveness of antibodies-mediated immunity to guarantee the accuracy of an “immunity passport” or “risk-free certificate,” for the COVID-19.
It stated that as of April 24, 2020, no study had evaluated whether the presence of antibodies to SARS-CoV-2 conferred immunity to subsequent infections by the virus in humans or not.
The WHO was reacting to suggestions by some governments that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, could serve as the basis for the issuance of an “immunity passport” or “risk-free certificate”.
This certificate they propose would enable individuals to travel or to return to work assuming they were protected against re-infection.
However, the WHO in its scientific brief, released on Friday, April 24, said there was currently no evidence that people who had recovered from COVID-19 and had antibodies were protected from a second infection.
Considering the measurement of antibodies specific to COVID-19, the brief said the development of immunity to a pathogen through natural infection was a multi-step process that typically took place over one to two weeks.
This it noted, could cause people who assumed that they were immune to a second infection – because they had received a positive test result – to ignore public health advice.
The use of such certificates may, therefore, increase the risks of continued transmission of infections.
The WHO said, it had, therefore, published guidance on adjusting public health and social measures for the next phase of the COVID-19 response.
