We live in an open society, in which social relations are marked by individual freedom, personal responsibility, and mutual trust. In an open society, we rely on people to make their own risk assessments in matters of personal and public health, without the need to carry health certificates on them at all times, or be under constant public surveillance.

We do not request identification from people to enter a supermarket. We do not request any special blood or saliva tests from people as a condition for attending a concert, museum, or restaurant. Social life, in principle, is open to all law-abiding citizens, and nobody has to disclose their family history, genetic makeup, or health status, in order to set foot in a social venue.

If Covid-status certificates are introduced, as they already have been in Israel for access to cinemas, concerts, sports events, and restaurants, all of this will change. Under a Covid passport regime, if you cannot or do not wish to disclose your personal health status, or submit to an intrusive Covid test, or inject a vaccine into your bloodstream, you may find yourself cast out of respectable company.

Apparently, vaccine-based discrimination for purposes of travel and socialization is now considered perfectly appropriate by some of our politicians. Just recently,  Tánaiste Leo Varadkar, speaking on the Dermot & Dave Show (Today FM), remarked in a rather off-hand way that people reticent about taking a vaccine “may change their minds if being able to travel, attend mass events, and things like that, is linked to it.”

What he was implying, in a rather cavalier way, was that persons reluctant to take a Covid vaccine might be pressured into doing so through rules that discriminated against the unvaccinated when traveling or attending large social events.

The fact that such a high-ranking politician could make such a comment so lightly, and get minimal blowback for it, tells us a lot about just how insensitive our public sphere has become to the values of a free, inclusive and open society.

If the Tánaiste had suggested that Travellers, or women, or black people, should be excluded from “mass events” or required to jump through extra hoops, as a condition for entry, he would have been accused of being sexist, racist, or bigoted. But it appears that institutionalising barriers to social participation for unvaccinated citizens is just fine.

Is it? At first glance, some form of proof of immunity or non-infectiousness, whether for domestic or international use, may seem like a reasonable solution to minimize the spread of an infectious disease like SARS-CoV-2. However, the introduction of health passports into everyday life raises profound ethical questions.

First, there is the issue of informed consent to medical treatment and experiments, a right firmly entrenched within the legal, medical, and social systems of many countries across the world, including Ireland. Every patient has the right to freely consent to or refuse medical treatment, whether of an experimental or routine nature.

While a Covid-status passport would not directly mandate vaccination, it would make social life and travel significantly more burdensome for those who opt, for health reasons or on conscientious grounds, not to vaccinate, placing significant social and legal pressure upon citizens to have a vaccine injected into them.

Second, a health pass would involve a fundamental transformation of the way we socialize, authorizing event managers and airlines to exclude unvaccinated clients or repeatedly subject them to intrusive PCR or antigen testing. Those who opt out of vaccination programmes might well find themselves occupying a new social “underclass”: not of race, national origin, or economic status, but of documented health status.

Now, if a Covid passport system stood a fighting chance of making more than a marginal difference – of heavily reducing infection and disease levels – then there might be a pragmatic or moral case to be made for requiring people to document their Covid health status for the purposes of traveling or attending some public events.

The trouble is, on its face, it is hard to see how a Covid passport is likely to make much of a dent on a globally endemic virus, especially one that poses a minimal threat to the vast majority of citizens. The risk SARS-CoV-2 poses to life and health, though real, is highly concentrated in the elderly and those with significant health complications, and dramatically lower for people under 60 without serious health issues.

There is no reason why vaccination of vulnerable populations should be insufficient to bring Covid risks within manageable and acceptable levels. Pressuring young people to vaccinate is simply unnecessary, from a medical and epidemiological perspective.

Covid passports are not just unnecessary to manage Covid risk; they are also likely to be rather ineffective at reducing infections. SARS-CoV-2 has been shown in numerous contact tracing studies to spread principally in intimate settings like households. For every social encounter that is controlled by an immunity pass, there are likely to be hundreds, even thousands, that are not. As such, a scheme of Covid passports would be unlikely to change the fundamental dynamics of a disease that is already globally endemic.

These considerations suggest that the net benefits of this method of health surveillance for protection of life and health, whether in international travel or in social life, would be marginal. It is hard to see how these marginal gains could justify the significant ethical hazards of such a scheme.

By raising special barriers to social participation for the unvaccinated, Covid status certificates would effectively create a two-tier society, divided into the vaccinated, who can travel and socialize freely, and the unvaccinated, who must submit repeatedly to costly and unpleasant tests. This looks very much like a recipe for social exclusion, public unrest, and political instability. Only time will tell if Covid passports become the new “normal,” and if so, how severe and far-reaching a form of medical apartheid they will unleash.