At a recent focus group on “vaccine passports”, a participant worried that the term “vaccine passport” was too intimidating. A passport is, for most of us, a special document used only in special situations. A better name, it was suggested, is “immune certificate”, presumably since we tend to think of a certificate as something you hang on the wall or stuff in a drawer, not a vital document one carries around. But switching terms in this way can occlude the issues at stake. The names we give to things should reflect their functions. If I go for a swim at the local pool, the attendant won’t ask to see my 25-metre swimming certificate or refuse me entry or confine me to the shallow end if I can’t produce it. By contrast, if I go abroad, a whole roster of officials will demand to see my passport and, if I can’t produce it, then, alas, no holiday in the sun for me. If the proposed Covid-related documents act as a way of allowing or refusing entry, then they are functioning as passports, not as certificates. In that case, use of the term “certificate” would be deeply misleading.

Covid vaccine passports are different because they would likely apply to movement within one’s home country

I offer this as an example of the ways that discussions about vaccine passports can fall foul of bad reasoning habits, ones that can conceal important subtleties and complexities. No matter what one thinks about passports, or whatever we call them, they clearly raise all sorts of moral, legal, and bureaucratic problems. There are reasonable concerns that they threaten to encourage stigmatisation, discrimination, social exclusion, dampen economic and social activity the country desperately needs, and by their nature expand state surveillance systems. Some of these concerns are most salient for the socially and economically vulnerable: those who are poor, who have lost their jobs, the black workers who are more likely to be fired, those who have run through their savings, or live in fear of eviction, or suffer economic and food insecurity. Even if none of these apply in one’s own case, there is a well-established moral and prudential principle that medical treatments shouldn’t be coerced. Moreover, bad reasoning about vaccine passports should concern everyone who thinks public health policy should be the product of clear, careful, and critical deliberations sensitive to a range of values, communities, concerns, and perspectives — whatever one’s own position on them. 

A reasonable worry is that current debates about “vaccine passports” are showing the signs of various kinds of poor reasoning and dodgy strategies of persuasion, ones that call into question the conclusions reached. Reasoning about complex possibilities is always tough, but especially when they involve contested issues being debated under conditions of anxiety and uncertainty. To illustrate these sorts of poor reasoning, let’s look at an example: the sanguine, shoulder-shrugging attitude that portrays the many concerns about vaccine passports as too trivial or tractable to merit anything more than a shrug.

Shoulder-shrugging and sanguine acceptance
A common lament of sanguine enthusiasts for vaccine passports is that they “don’t see what all the fuss is about”. Sometimes, the problems aren’t obvious to them, or they do see what people are worrying about but think it’s easily dealt with — so why all the bother? With any contested issue, there are always shoulder-shruggers. Some fail to see the problems. Some don’t share the concerns. Some refuse to “indulge” what they see as the groundless anxieties of the worriers who are then often derogated as “nit-pickers”, “tree huggers”, “die-hards”, or whatever insults seem apt.

With any contested issue, there are always shoulder-shruggers. Some fail to see the problems

For sure, there are plenty of cases where people do make a fuss over nothing. Many people enjoy storms in teacups. But issues raised by vaccine passports shouldn’t be dismissed as fuss and bother over nothing. Sometimes one fails to see the problem because it takes training or experience to see it and certain moral or political sensibilities to register it as an issue. But not seeing a problem is no guarantee there isn’t one: maybe we’re failing to see what better trained, more experienced people spot straightaway. If the reasons for people’s hesitation does “elude” us, we should redouble our efforts to grasp them. If the World Health Organisation, Liberty UK, and writers in The Lancet and British Medical Journal urge caution about vaccine passports, then why not accept, in a spirit of humility, that there are genuine issues at stake that shouldn’t be insouciantly dismissed as “fuss”?

Some enthusiasts for vaccine passports, to be fair, do offer reasons, arguments, and appeals to precedent. A favourite one, at the moment, involves noting that travellers already need an International Certificate of Vaccination or Prophylaxis before travel to areas where yellow fever is found, like countries in sub-Saharan Africa and central and South America. But there are important differences between those cases and Covid-19, including the differences in the transmission mechanisms and case fatality rates for yellow fever and Covid-19 and the fact that Covid-19 vaccine passports would likely apply to everyday movement within one’s home country, rather than travel to other countries.

Others point out that doctors and nurses must have hepatitis B vaccinations, such that the concept of vaccine passports is “not totally alien to us.” True enough, but — again — there are important differences between those mandatory hepatitis B vaccinations for healthcare practitioners and Covid-related vaccine passports for the public. Consider the very different transmission mechanisms: hepatitis B is mainly transmitted perinatally or by contact with the bodily fluids of infected persons or by use of infected needles or syringes. Moreover, the fact that a concept isn’t “alien” does not automatically justify extending the practices it justifies to other groups or wider areas of life.

Confronted with sanguine shoulder-shruggers who fail to see or acknowledge all those complexities inherent in vaccine passports, the response shouldn’t be acquiescence. It should be to challenge them to provide neat solutions to the moral, legal, technological, and practical challenges which are currently occupying the British Government, experts in health and social care policy and ethics, leading civil rights and liberties organisations, data ethics institutes, and leading global health agencies.

Necessity and efficacy
Some enthusiasts for vaccine passports concede these and other problems, but insist that we should accept them because of the most vital consideration: the need for vaccine passports to protect public health against the ongoing threat of Covid-19. Vaccine passports may pose all sorts of problems that are tough to deal with, but they are our best or only way back to normal. According to this argument, vaccine passports may well be difficult, but they’re also essential. (Here, we should ignore denialists and conspiracy-mongers who insist that there is no virus at all, an absurd claim “justified” on all manner of spurious grounds.)

The efficacy of a vaccine passport is called into question by the sheer range of epidemiological variables at play

The efficacy of a vaccine passport system is called into question by the sheer range of epidemiological variables at play. There are currently a range of vaccines — four approved in the UK with others being trialled — that offer different degrees of protection against different variants. Moreover, there’s the diversity of individual immune responses among vaccinated people. Some got one jab, some got two. Some got an AstraZeneca, some got “Pfizered”. Some have robust immune systems, others don’t. Such individual variations reflect differences due to age, genetics, lifestyle, infection history, and so on. All of this creates enormous problems in evidencing changing degrees of immunity (here, here). This doesn’t call into question the efficacy of vaccines, but rather the operability of vaccine passport systems.

It’s remarkable so many are so confident that these complex, changing immunological responses can be glossed into a certificate saying “IMMUNE” next to a big green tick — a worry raised by the World Health Organisation. A can-do “We’ll work it out!” attitude is remarkably self-assured given the uncertainties and variables. If the worries are well-founded, we are at risk of ending up with a system at once pointless and impossible, as well as expensive and intrusive, none of which are desirable features of a public healthcare system. Remarkably, some commentators are utterly confident about our capacity to manage these uncertainties. A professor of paediatrics, in a recent American Medical Association discussion, suggested we get around uncertainties about the duration of protection by recording dates of vaccinations and then adding six months. As an easily doable method, that may work. As a response to the immunological complexities, though, it leaves much to be desired.

Confronted with looming problems, it’s natural to want to adopt a stance of sanguine confidence and project a “can-do” attitude that encourages hope. Unfortunately, we have to balance that natural desire against other considerations, like the necessity and workability of what’s being proposed, and the diverse worries raised by groups who are likely to be affected in different ways. Taking all this seriously complicates our debates about vaccine passports, but at least we might then be confident that we are properly reckoning with the actual moral, practical, political, cultural, and epidemiological issues at stake.