The World Health Organization has put the brakes on one highly touted mechanism to get the world economy up and running again.
The idea of "immunity passports" or "risk-free certificates" based on antibody testing is a false hope, the WHO said in an April 24 news release.
"There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection," the WHO said.
In addition, the antibody tests for SARS-CoV-2, the virus that causes COVID-19, could promote a sense of false security about the virus, which is called the new coronavirus for a good reason — we don't know much about it.
The science of viruses and immunity
Germany was one of the first to float the idea of "immunity passports" to get millions of people back to work after the first wave of the COVID-19 pandemic.
The country's public health agency is in the middle of conducting a study to analyzing blood samples from 100,000 people.
Researchers are looking specifically for coronavirus antibodies, blood proteins the body churns out when it detects foreign substances like bacteria and viruses.
As Futurism notes, the presence of antibodies in the blood indicates that the body has mounted a defense against the virus — and lingering antibodies would suggest that the battle has been won. In this way, a population could reach "herd immunity," meaning the majority are no longer susceptible to the disease. People who are infected wouldn't be able to spread the disease so easily among a mostly immunized group.
And while this has proven true of other viruses, we don't know if it's true for this one.
The WHO says it supports the antibody tests, which have been conducted in health personnel and in the cases of people who have had known contact with someone who has tested positive for the virus.
"These studies will provide data on the percentage of people with detectable COVID-19 antibodies, but most are not designed to determine whether those people are immune to secondary infections."
Where things get fuzzy
The thinking behind the antibody tests is that once you get the virus — and fully recover from it — you should be immune. But there is no certainty.
The trouble is we simply don't know for certain whether people who have had COVID-19 gain immunity to the virus. The antibody tests look for signs of infection from any of the six known coronaviruses — four that cause the common cold, one that cases Severe Acute Respiratory Syndrome (SARS) and one that causes Middle East Respiratory Syndrome (MERS).
An infection from any of them could muddy the test results, creating false positives and false negatives.
Beyond the medical questions, there are logistical ones. How do you enforce the new immunity approval system? As Quartz spells out, that step raises a new slew of questions.
Will police go around parks and offices and hospitals checking everyone’s documents or QR codes on their phones to ensure those who are out and about really are safe? Will societies create a new class of privileged worker who, by virtue of prior infection, is now a more desirable citizen from an employment perspective?
Much of the workings of the novel coronavirus — and certainly how to stop it — remain a mystery.
It doesn't mean we stop trying to find solutions, but for every step forward, we may have to take a step back.
Editor's note: This story has been updated since it was first published in April 2020.