There is no evidence that people who have beaten coronavirus are protected from the strain, the World Health Organisation has said as it warned against issuing "immunity passports".
The concept of “immunity passports” or “risk-free certificates” has been floated as a way of allowing people protected against reinfection to return to work.
But the Geneva-based UN health agency said in a scientific brief published on Saturday that more research is needed.
The news comes as more than 2.5million have been infected with Covid-19 around the world according to Johns Hopkins data.
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’.”
It argued that people who assume they are immune to reinfection may ignore public health advice and that such certificates could raise the risks of continued virus transmission.
The WHO added that tests for antibodies of the new coronavirus also “need further validation to determine their accuracy and reliability”.
