WHO warns immunity passports may increase spread of coronavirus

The World Health Organization is advising against the concept of 'immunity passports,' which would be certificates proving that someone has contracted and recovered from the novel coronavirus. The idea behind the passports is that someone who contracted the virus will have antibodies, potentially making them immune to the virus and therefore risk-free. WHO warns there's no evidence to support this idea.

Governments around the world are working on ways to start opening back up society, a process that will likely be gradual and that must be made with caution in order to prevent an uptick in COVID-19 cases. Assuming one develops an immunity to the virus after recovering from it, 'immunity passports' could be a way to let some people return to normal activities without increasing the spread of the virus.

The problem, however, is that it is not yet known whether someone who has recovered from the coronavirus is actually immune to it. Select cases of re-infection have popped up around the world and experts haven't yet said definitely whether these are instances of false positives or some other factor.

In its statement on Friday, WHO said that it is still reviewing evidence of antibodies in cases of the coronavirus. The agency explains:

Most of these studies show that people who have recovered from infection have antibodies to the virus. However, some of these people have very low levels of neutralizing antibodies in their blood, suggesting that cellular immunity may also be critical for recovery. As of 24 April 2020, no study has evaluated whether the presence of antibodies to SARS-CoV-2 confers immunity to subsequent infection by this virus in humans.

WHO points out a second issue that is also complicating things: inaccurate tests. Until rapid diagnostic tests can be developed that are demonstrated to have a high level of accuracy, it is possible that some people may test positive for antibodies when they are, in fact, still at risk of the virus. This, the agency warns, may increase the spread of the virus.