COVID passes: they can’t prevent every infection but do make events safer

COVID passes lower the risk of transmission and incentivise vaccine uptake at a time when boosters are desperately needed.

Photo by Mat Napo on Unsplash
Photo by Mat Napo on Unsplash


With more than 60 countries now reporting cases, omicron has policymakers scrambling. Compared to delta, this new variant is likely to be more infectious and less responsive to one or two doses of a COVID vaccine.

It remains unclear how severely ill it makes people. Reports from South Africa suggest it may not be quite as deadly as delta, but the large number of prior infections there could be keeping hospitalisations down and masking the variant’s capabilities.

Even if milder, omicron’s increased transmissibility risks a tidal wave of cases that would strain already exhausted health services and take many lives. Given how quickly the variant is spreading, it’s clear that a spike in cases is inevitable – the question is to what extent it can be mitigated.

This is why new attention is being paid to an old idea: COVID vaccine passes. Already in use in Scotland, Wales and Northern Ireland – as well as in many other parts of Europe – these passes show that a person is fully vaccinated for COVID or has recently tested negative.

They’ve now been introduced in England, too, and are mandatory for entering large high-risk venues. This includes nightclubs, indoor unseated venues with more than 500 people, outdoor unseated venues with more than 4,000 people, or any venue with more than 10,000 people.

Introducing them has been contentious within the government’s own party. Nearly 100 Conservative MPs opposed the measure, making this the largest rebellion of Boris Johnson’s premiership.

Much of this dissent stems from concern about the role of the state in people’s lives. Some see vaccine passes as excessive coercion; as anathema to deeply held moral convictions that the state should not unnecessarily limit the freedoms of its citizens.

Those on the other side argue that they can play a vital role in reducing the impact of COVID this winter and could save many lives. But are they right?

Do they stop transmission?

There are legitimate concerns about how effective vaccine passes are at containing the virus. And it’s clear they won’t prevent transmission at high-risk venues altogether.

At the Boardmasters Festival in Cornwall in August 2021, for example, all attendees had to show either a recent negative test result or that they were fully vaccinated. Despite this, and the festival being open air, an estimated 4,700 subsequent cases were linked to the event. There are several explanations for this.

Rapid tests represent just a single point in time – so it’s possible for someone to be infected or become infectious between taking a test and attending an event. They also occasionally give false negative results: saying people don’t have COVID when they do.

And although most fully vaccinated people will be protected from the worst effects of the virus, some can still get COVID. The strength of each person’s vaccine response differs, and immunity wanes over time. Omicron also seems more able to infect those who’ve only had two vaccine doses (which, for the time being, counts as being fully vaccinated).

All of this means that a vaccine pass cannot provide a perfect assessment of an individual’s risk of transmitting the virus.

However, they may stop some infectious people from mixing in crowded areas, in turn preventing some (albeit not all) cases. An analysis from the Tony Blair Institute for Global Change suggests that if the British government had made COVID passes mandatory after lifting restrictions in July, this could have reduced cases and deaths over the subsequent weeks by as much as 30%.

Incentivising vaccination

The evidence on reducing transmission may fail to persuade some, but COVID passes have another objective: they can be a powerful incentive to get vaccinated, particularly among younger groups who may be more ambivalent about vaccines.

A recent study that assessed their impact in Denmark, Israel, Italy, France, Germany and Switzerland found that COVID vaccine uptake increased in the 20 days prior to passes being introduced, with this effect lasting for up to 40 days afterwards.

A young person after being vaccinated
Passes have proven an effective driver of COVID vaccination in younger people. Mrz producer/Shutterstock

Passes were most effective at driving uptake in people under 30, and they had a greater influence on younger people when needed to access certain settings, such as nightclubs or events attended by more than 1,000 people. Note that this was a relatively high-quality study. It used a statistical design that evaluates real-world impact by simulating the conditions of a randomised trial.

This is important given that vaccine boosters appear to significantly increase protection against omicron. Ensuring that people get boosted is therefore essential. Indeed, the UK health secretary has said that having a booster will soon be required to count as being fully vaccinated.

Bolstering our defences

Still, critics will claim that COVID passes are an example of state overreach – a breach of fundamental rights and freedoms.

But the UK Human Rights Act guarantees every individual a right to liberty and security. This includes protection from the threat of infectious disease, particularly in the context of public settings. The government therefore has a moral obligation to do what it can, with the knowledge and resources it has, to control the spread of COVID.

The government is not alone, either. There’s public support for vaccine passes across Europe. In the UK, 64% of those polled support their use for large indoor events.

It’s also worth remembering that for the wave of omicron on the horizon, epidemic control options are limited. Alternatives – such as mandatory vaccination, or lockdowns – are typically more contentious. Lockdowns also have long-term health, economic and social costs.

We must be careful not to let the politics distract. We know what works: taking up a booster jab, working from home, social distancing, hand hygiene, face masks, ventilation, regular testing, and isolation for those with symptoms. Vaccine passes will not revolutionise our COVID response. But they could prove to be a useful addition to this list.The Conversation


Vageesh Jain, NIHR Academic Clinical Fellow in Public Health Medicine, UCL

The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Disclosure statement

Vageesh Jain is affiliated with the UK Health Security Agency as a Specialty Registrar in Public Health, which does not involve any work on domestic public health policy.



University College London provides funding as a founding partner of The Conversation UK.