Vaccine rollout is advancing at snail pace in the European Union. At the same time, countries like the United States, the United Kingdom, and Israel are moving quickly to get large parts of the population vaccinated as promptly as possible. As Europe debates the success or failure of its vaccine policy, some countries want to be one step ahead and discuss the possibility of so-called vaccine passports.

The concept is straightforward: those who have been administered with a COVID-19 vaccine will be able to have access to international travel, inter-country travel, bars, restaurants, or concerts halls. In essence, this measure would extend lockdown rules for those who do not receive the vaccine indefinitely while giving vaccine receivers a free pass. In Europe, Greece is advocating for an EU-wide measure, while Poland is already implementing local solutions.

First, these kinds of measures pose a severe problem to the rule of law. That is, government-mandated vaccinations are hardly compatible with the concept of individual liberty. Medical choices are personal choices. While insurance companies should be able to make decisions about payable premiums for diseases contracted that a vaccine exists for, it is not the government’s business to make health decisions for citizens. Furthermore, if governments do not mandate a vaccine administration, they should also not restrict the movement and liberties of those who did not receive it. A second-class citizen model is deeply illiberal.

Far more interesting than those questions of principle (at least for policy wonks) is that of EU internal border disputes. Let’s assume that Greece requires vaccination to enter the country when France does not (as a side note, France is unlikely to mandate vaccination, because the population is already profoundly skeptical of vaccination). Someone flying from Paris to Athens would move within the Schengen Area, thus should not be required to provide identification. However, a vaccine passport would require cross-checking vaccine info with ID cards, making the continuation of the Schengen ideal impossible.

Airlines only check ID cards to cross-check their ticket information with the person boarding, but that is purely the companies’ prerogative, and those who travel a lot will know that not all airlines are thorough on this issue. Outsourcing the vaccine obligation to airlines will be neither practical nor necessarily legal. Let’s note that this is only addressing airlines so far, which are a relatively straightforward method of travel (entry and exit are easily identifiable). What happens to crossing sea borders by ferry, cycling over a mountain, or simply driving with a car? Vaccine passports would, in essence, be backed through randomized checks.

Randomized border checks upon a whole new Pandora’s Box, and a more fascinating one at that. ID card checks aren’t legal in all EU member states, because law enforcement needs reasonable suspicion to ask for ID (thankfully so). In those countries, randomized vaccine passport checks would be equally illegal. Those countries that practice randomized checks will be confronted with multiple new layers of human rights clauses and constitutional restrictions, not least the European Court of Justice which would need to decide if a French citizen in Athens can be required to show a vaccine passport at a randomized airport arrival check.

The pertinent question is: why is this a big deal? Countries are currently using testing requirements for COVID-19, all while cross-checking with ID cards. Would adding a vaccination passport requirement be any different? Questionably in line with the Schengen Treaty, governments have done this exact thing given the pandemic’s unusual circumstances. However, you can note that Hungary (provision expiring on January 28, 2021), Denmark, Norway, and Finland are the only countries having required formal exemptions from the Schengen Agreement.

Legal shenanigans or not, vaccine passports are a terrible idea for a multitude of reasons. Law enforcement is known to accumulate too much power to “protect” citizens, and that is very resistant in returning powers once the crisis is over. 9/11 and subsequent terrorist attacks in Europe have demonstrated how fragile the civil rights narrative really is. On top of that, mandating vaccination or incentivizing it through the back door won’t build trust — it will foster suspicion.

Countries are ill-advised to introduce vaccine passports at this stage or any stages in the future.