With the global economy in freefall as worldwide COVID-19 cases surpass 2 million this week, officials in hard-hit countries are suggesting that so-called 'immunity passports' may be a path back to economic stability, according to France 24.
The way it would work is that those who have already had the disease would be assumed to be immune, and would be given permits to conduct their lives like they did before the pandemic.
Shortly after emerging from self-isolation after testing positive for Covid-19, the UK’s Health Secretary Matt Hancock announced in early April that the British government was considering an “immunity certificate” system to allow those who qualify to “get back as much as possible to normal life”.
Paris Mayor Anne Hidalgo has also given the idea her backing – putting it in a list of proposals for returning to business as usual in the City of Lights that she sent to the French government. On the other side of the Atlantic, Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, told CNN that immunity passports are “being discussed” in the Trump administration. “It might actually have some merit under some circumstances,” he added. -France 24
There are a few problems with this idea. For starters, nobody knows how long immunity lasts.
"At this point, the virus has been widely circulating in Europe and North America only for a couple of months, and so that is all the information we have – we will know in a year if immunity lasts a year; we will know in two years if immunity lasts two years," said Abram Wagner, an assistant professor of epidemiology at the University of Michigan. "From past research into other coronaviruses, immunity was not long lasting, and I would not be surprised if, for most people, immunity lasted less than one year."
Second, antibody tests are not 'sufficiently accurate' at this point, according to Georgetown University Center for Global Health Science and Security assistant professor Claire Standley, so added "we are still a long way off it being useful to test individuals with these methods."
A major reason why such tests look likely to be ineffective, Standley explained, is that they do not seem specific enough to avoid mistaking a similar virus for Covid-19: “There may be cross-reactivity between the antibodies for SARS-CoV-2 [Covid-19] and other circulating coronaviruses – including those that cause common colds – meaning a positive result might not indicate past exposure to SARS-CoV-2 but maybe another coronavirus instead.”
Standley also warned that the tests can fail to detect those who have experienced a minor case of COVID-19, noting that "High false negative rates (lack of sensitivity) of the test mean that those currently available are not recommended for patient-level clinical diagnosis; unless the sensitivity improves, these tests may also not be effective in identifying people who have recovered from mild cases of Covid-19, and thus may have lower levels of antibodies in their blood."
A third issue is concerns over the social implications of immunity passports.
"I suspect many people will be resentful if others were able to return to work and make money because they had an immunity passport," said Standley, adding "I have grave concerns about how these types of schemes could be implemented equitably and fairly, even assuming a reliable antibody test were available, and more known about the length of immunity and how protective it is."
"If the tests need to be purchased, this could further exacerbate disparities between those who can afford the tests (and who may already have been able to work from home/maintain an income during lockdown) versus those who cannot, and thus would be further barred from re-entering the workforce.," added Standley.
Lastly, Standley suggested that immunity passports would create a perverse incentive to contract the disease.
"In an effort to return to work, or allow their children back to school, will the promise of an immunity passport make people behave less responsibly, and risk infection, in order to end up with a positive antibody test?" Therefore "The scheme would potentially punish those citizens who have behaved responsibly and tried their best to reduce their own risk of exposure and that of transmission within their communities."