After initially resisting the idea of Covid passports, the government has decided to introduce them in “higher risk” settings in England, such as nightclubs and large crowds, by the end of September in an attempt to coax young people into getting vaccinated. Although the details of this measure are yet to be released, it will probably involve showing proof of vaccination, a negative Covid test or recent recovery from the virus.

The plans for England’s vaccine passports were announced shortly after France introduced its hardline “health pass” approach, which requires people entering restaurants, cinemas, trains and shopping malls to show proof of two vaccinations, a recent negative Covid test or recent recovery from infection. News of France’s health pass sparked mass protests; an estimated 160,000 people took to the streets on 24 July. But it also stimulated vaccine uptake. Nearly 4 million people came forward to get vaccinated after the health pass was announced.

Many seem to think vaccine passports are a viable solution that would encourage uptake and allow businesses to remain open while ensuring restaurants, bars and nightclubs don’t become Covid hotspots. Yet introducing a passport would be a technical and ethical minefield, and a number of criteria would need to be met, ranging from how immunity is measured to what technology is used, and what ethical requirements it meets. The technology would need to work across multiple operating systems and be linked to personal information while also maintaining privacy. But beyond these concerns, would a Covid passport actually work?

At the end of June, the Netherlands introduced the type of passport that is currently being proposed in England. Its CoronaCheck app crumbled within hours of release. People were required to have a negative test, proof of vaccination or recovery. The passport was aimed at nightclubs, but on the first night, a report filmed drunken partygoers explaining how they used the negative test results of a friend to gain entry and found ways around the QR code.

The app was clever: in addition to proof-of-vaccine or a test, it requested limited personal details (your initials and part of your birthdate), while its constantly changing QR code avoided privacy and tracking concerns. But the weak link was that bouncers rarely checked the app against personal identification, since this would have required additional staff on the door. Perhaps the UK government has developed a more advanced solution, but I’m not optimistic. The only way I could obtain settled status in the UK was by borrowing an Android phone from a colleague, as the government application form didn’t work on an iPhone.

Like much of its pandemic response, the government’s Covid vaccine passport shifts responsibility from ministers to individual members of the public. First we were asked to use our “personal judgment” for when and where to wear face coverings. Now nightclubs will become the referees for whether people are safe to enter. In France, a vaccine passport will apply across restaurants and other venues, but in the UK, nightclubs – which generate an estimated £66bn annually and are responsible for 8% of the country’s employment – have been singled out by the government. If businesses now work towards hiring staff and implementing new Covid passes only for the policy to change in September, their preparations could be in vain.

Public health experts and behavioural scientists have long argued that policies nudging people or dangling incentives like a carrot are more effective than the stick. Although it seems hard to fathom now, there was considerable backlash over mandatory introduction of seatbelts, and it took years to ban smoking on public transport and in indoor spaces. Again, the concern was how far the state could interfere with personal rights and lifestyle. In the US, where there are large numbers of vaccine-hesitant people, states have introduced incentives ranging from free guns and beer to million-dollar lotteries. Yet a recent study found that it wasn’t coercion that worked, but the personal approach of a text reminder saying this vaccine is “reserved for you” that was the most effective in getting people vaccinated.

There is a risk that a mandatory Covid pass will be seen as coercive, fuelling greater mistrust around vaccines. Requiring an ID card or passport to enter a football match or nightclub could fuel suspicion for those against the use of Covid certification. We carried out a nationally representative survey of 1,476 adults in the UK in December 2020 during the first vaccine rollout, together with five focus groups, and found that those who are distrustful of government and receive information from unregulated social media sources such as YouTube were less willing to be vaccinated. For Covid conspiracists, a vaccine passport may have the same symbolic effect as the face masks that have so riled anti-lockdown protesters.

When dealing with public health measures, it’s naive to argue a straightforward libertarian case that the government should stay out of people’s private lives. As with secondhand smoking, the government has a moral duty to stop the spread of Covid, and promote and safeguard the health and wellbeing of its citizens. Policies that curtail individual liberty for the greater public good can be powerful, but they need to be properly scrutinised to ensure they work. That means avoiding unjustly coercive measures that will only produce more harm than protection.