Holding people responsible

Defenders of vaccine passports for international travel argue that it is ‘only fair’ to require people to ‘bear a consequence for their refusal’ to vaccinate.9 Yet, globally, not everyone gets to choose. As noted already, 85% of vaccines have been administered to people in HICs or upper-middle-income countries. As of June 2021, the cumulative number of doses administered per 100 people ranged from over 100 in Israel and the UK, to 3 or fewer in South Africa and Guatemala.15 It is unfair to ask people without access to vaccines to bear the consequences of a ‘choice’ they never made. Nkengasong, the head of the Africa Centers for Disease Control and Prevention, described passports as ‘inappropriate’ under current conditions, where LMICs lag so far behind HICs in equitable access to vaccine; in a press conference, he put the point this way, ‘any imposition of a vaccination passport will create huge inequities and will further exacerbate them.’16

Protecting global health

A second defence of vaccine passports appeals to the fact that although they impose a requirement for vaccination and certification, they are ethically justified to protect health and save lives. Passports incentivise vaccinations by giving advantages to people who get vaccinated, and for this reason, may help end the pandemic sooner. However, the reason the world is unsafe is not that people in LMICs refuse to vaccinate; it is that they do not have access to vaccines. Allocating more of the world’s vaccines to LMICs in Latin America and Asia would protect global health far more than closing down travel for people living in poorer places. Ultimately, it will keep vaccinated people safer too, reducing the odds that new mutations of the virus will emerge that prove impervious to protections afforded by vaccines and prior infection.

Still, a defender of vaccine passports might argue that the world has stepped up already and given vaccines to poorer nations. In June 2021, leaders of the group of 7 pledged 1 billion doses of COVID-19 vaccines to LMICs through COVAX, the international partnership that aims to accelerate development of COVID-19 vaccines and distribute them equitably.17 Why not continue such efforts and, in tandem, implement vaccine passports for international travel? In reply, at the current rate, there will not be enough vaccines to cover the world’s population until 2023 or 2024.18 If, during the intervening years, wealthy nations form their own exclusive travel club, shunning people from poorer nations, what message does that send? How could it not leave a lasting mark on international relations for years to come?

Safeguarding individual liberties

Brown et al mount a defence of vaccine passports that appeals to ‘a strong presumption…in favour of preserving people’s free movement if at all feasible;’ they go on to argue that passports protect this by allowing vaccinated people to come freely together and travel where they like.8 In reply, it is helpful to ask, who is freer with vaccine passports and who is not? Vaccine passports for international travel would ban many COVID-negative people in LMICs from flying because they do not have access to vaccines. By contrast, the current approach to international travel, which typically requires a negative COVID-19 test, is far less restrictive, because testing is much more widely available than vaccines are.

Yet a proponent of passports might object that people living in LMICs don't travel much anyway, precisely because of their low incomes. In reply, this objection is self-defeating. If people in low-income nations don't travel much anyway, why do we need vaccine passports to prevent them from travelling?

A proponent of vaccine passports could argue that vaccine passports encourage people in wealthier countries to travel to LMICs as tourists, which is a boon to these economies. Yet, in reply, travel can also spread disease to unprotected regions. While there is encouraging preliminary data about transmissibility of the SARS-CoV-2 virus with two mRNA vaccines (Pfizer and Moderna),19 uncertainty remains about the ability of these and other vaccines to prevent transmission, and transmissibility may vary depending on the virus strains circulating in a particular region.

Finally, an endorser of vaccine passports might say that there is no ‘right to travel,’ so even if vaccine passports restrict the movement of many people in LMICs, they do not violate their rights. However, in response, many hold that moving freely from place to place is a basic liberty and overriding it demands a special justification. Gostin and Chertoff argue that liberty deprivations, including travel restrictions, must be justified on the basis of sound science and careful balancing of public health and individuals’ liberty interests.20 They argue that public health restrictions should be the least restrictive means to achieve a public health goal. In the case of vaccine passports, less restrictive means than vaccine passports are available to keeping the public safe (discussed in section III).

Continuing current practice

Osama et al endorse vaccine passports on the ground that the world is already using them, so it only makes sense to apply them to COVID-19 vaccines.21 Citing the example of yellow fever, they note that the WHO endorses certificates confirming vaccination against yellow fever for entry into certain regions where it is endemic.

However, vaccine requirements for yellow fever are nothing like proposals being floated for COVID-19. With COVID-19, we have witnessed a rapid, mass roll-out of a variety of vaccines with a range of efficacies and no agreed on standards for scientific authorisation, monitoring and documentation. By contrast, the yellow fever vaccination is a single shot, using a WHO preapproved vaccine, administered in regulated centres with defined conditions for vaccine administration and documentation.22 In contrast to the SARS-CoV-2 virus, which is rapidly replicating and mutating with different strains circulating in different regions, yellow fever virus exhibits slower evolutionary dynamics and is limited to regions of Africa and Latin America where the infected Aedes or Haemagogus species mosquitoes are found. To be consistent, we would need to apply the same standard to COVID-19 certification that we apply to yellow fever certification; this entails not requiring certification of COVID-19 vaccination until we can do so using WHO-approved vaccines administered in regulated centres with defined conditions and documentation.

With COVID-19 vaccines, there remains significant uncertainty about the duration of protection and the possibility of transmission after vaccination (which is preliminarily established for some vaccines but not others). In light of this, passports could backfire, posing a threat to public health.

In sum, the arguments presented in this section point to grossly unequal access to COVID-19 vaccines across the globe as a strong ethical reason to hold off on using them.

Protecting public health

A strong argument for domestic vaccine passports is that they help people get their lives back on track and socialise safely with others, reducing social isolation and loneliness associated with lockdowns and sheltering in place. Reducing social isolation in turn, protects public health, because social isolation is a major social determinant of health. Social isolation predicts all-cause mortality at levels that match well-documented clinical risk factors, such as smoking, while eclipsing others, such as obesity.23 Vaccine passports seem like a smart and effective tool to prevent these untoward effects.

Yet, an important question is who would vaccine passports help and who would they hinder? To answer this, consider who has the greatest access to vaccines and who has the least. Socially marginalised groups, such as people who are poor, racial and ethnic minority, or displaced, tend to have less access than the general population. Vaccine passports would worsen health disparities if they excluded these groups from many areas of social life, increasing their social isolation.

Even in wealthier nations like the USA, where vaccines are in principle available to every adult, access is not equal; during the first 4.5 months of the US vaccination programme, high social vulnerability counties had lower COVID-19 vaccination coverage than did low social vulnerability counties.24 Part of the problem is that people in high social vulnerability counties have a harder time getting to large vaccination sites because they cannot afford time off work, transportation or lack internet access to obtain an online appointment.

Vaccine caution is a further reason for lower vaccination rates among socially disadvantaged groups. In the USA and other countries, cycles of unequal access to care and disproportionate exposure to health risks have eroded trust in medicine and science among racial and ethnic minority groups, which, in turn, feeds vaccine reluctance.25 For example, more than 90 days into the US vaccination roll-out, an Associated Press - NORC (Nonpartisan and Objective Research Organization at the University of Chicago) poll reported that Black Americans remained among the groups most likely to report reluctance to get vaccinated.26

An additional concern is whether enforcing vaccine passports would lead to racial profiling.7 The worry is that the credentials of certain demographic groups would be more often questioned and the message conveyed would be that they are not welcomed. Even the perception that this is happening could be divisive, leading to accusations and anger that fuel division.

In response to the above arguments, it could be objected that unless we implement vaccine passports to entice customers back to restaurants, shops and businesses, the economy will falter, which threatens public health too. In reply, there are other ways to open economies. Masking and physical distancing are fairer than vaccine passports as are methods of certification that are flexible (discussed in section III).

Preventing free riding

Another argument supporting vaccine passports holds that those who refuse vaccines are free riders. They get something for nothing, benefitting from population-level protection without contributing to it by getting vaccinated. It might be thought that vaccine passports prevent free riders from enjoying something for nothing.

In reply, this argument glosses over the diverse reasons that lead people to refuse COVID-19 vaccines, boiling everything down to free riding. Undoubtedly, some vaccine refusers do free ride. Many others refuse vaccines for practical reasons: they cannot take unpaid time off work, do not have affordable childcare or have a hard time getting to vaccination sites. Undocumented migrant workers may fear being deported if they go to a vaccination site where people in uniform ask them for identification. Others distrust the rapid roll out and emergency authorisation of vaccines, worry that scientists are beholden to politicians and regard for-profit companies as having a conflict of interest. They take a ‘wait-and-see’ approach and plan to get their shots eventually. False information fuels other people’s vaccine refusal, fed by rumours and conspiracy theories on unregulated e-commerce and social media sites.

Some oppose vaccines on the basis of deeply held religious principles. The fact that Johnson & Johnson used abortion-derived fetal cell lines to develop, test and produce their COVID-19 vaccine has met with resistance by some Catholic leaders, despite the fact that the Vatican has said, ‘it is ‘morally acceptable’ to take vaccines that used fetal cell lines in their research and production process.27

Others refuse vaccines based on a principle that places priority on individual welfare over benefits to the population.28 Public health discourse may encourage such a mindset when it uses the language of choice, empowerment, personal responsibility and participation that emphasises individual rights over duties to others.

Yet, proponents of vaccine passports might argue that conscientious objectors can be accommodated through conscientious objector exceptions. However, the downside of this strategy is that historically, people have looked askance at conscientious objectors, labelling them ‘bad citizens’ and accusing them of free riding.29 With new virus variants circulating that may diminish efficacy for some vaccines, the bar for population-level protection may rise, exerting more intense pressure on vaccine refusers to get vaccinated.