‘We shouldn’t emotionalize the discussion. It’s purely pragmatic’: An interview with Peter Jüni

Peter Jüni has served as the scientific director of the Ontario COVID-19 Science Advisory Table since July 2020. He has consistently voiced his view that vaccine certificates are indispensable to controlling the pandemic. We interviewed him about his stance on this issue, and what follows is a transcript of this interview, edited for length and clarity.

Why do you support using vaccine certificates?

People who are fully vaccinated are on average five to six times less likely to be infected with the virus that causes COVID-19; they’re about 92 per cent less likely to be admitted to hospital and about 97 per cent less likely to be admitted to the ICU.

So, when it comes to requiring vaccine certificates to access certain settings at higher risk of transmission, there are two important things to consider. Firstly, we protect those within the setting by only admitting people who have a lower risk of carrying the virus. And even if somebody does transmit the infection to others, if everybody is vaccinated, the outbreak is less pronounced, slower. Secondly, we keep those who are not vaccinated or only partially vaccinated out of trouble by keeping them out of high-risk settings, decreasing their risk of experiencing severe outcomes. So, if you have a vaccine certificate that is falsification-proof and accessible to everyone, you have a situation where the population in a high-risk setting is at considerably lower risk from both a transmission perspective and the perspective of developing medical complications.

The only way to deal with Delta while keeping society open and the economy going is to make sure that we can keep the unvaccinated out of trouble as long as possible to keep the curve flat for ICU admissions and hospital admissions. In Ontario, a little under 2 million people above the age of 12 are not yet fully vaccinated in a population of 13,034,000 eligible people. But these 2 million still have on average about a 0.7 per cent risk of ending up in an ICU, and of course, this average risk dramatically increases with age. If these people all got infected very rapidly, it would be very challenging for the health-care system.

You need a driving licence to drive on Ontario’s roads because it makes you safe and keeps others safe. That’s a relatively apt analogy for vaccine certificates. Nobody complains about driving licences. Why would they complain about certificates?

What arguments against the vaccine certificate are most persuasive to you? Where do you feel the most torn in your position?

What really worries me is that we have a lot of vaccine disinformation out there predominantly promoted by white-privileged people. But if this disinformation is widely believed, the communities that are disproportionately impacted are racialized communities, ethnically diverse communities, people who were exposed to systemic racism before, who are challenged with socioeconomic issues, who experienced perhaps totalitarian regimes before. This includes Black, Indigenous and people of colour, but also people from former communist countries, who experienced oppression. This distrust is justified, and the negative impact of disinformation in these communities makes me really angry.

What I hope for is what we see, for instance, in my home country of Switzerland: The vaccine certificates now nudge the people from former Kosovo to get vaccinated because it gets so inconvenient not to be vaccinated that they’d rather take the vaccine. This has a positive influence on the burden of disease these people are experiencing. So, I don’t even see that part as an argument against vaccine certificates.

The point that it’s dividing society is an absolutely invalid argument. There is this very small, very vocal minority of the anti-vaccine movement that will always be strongly opposed to anything we’re doing. The strategy that these people have is they suggest that there’s a legitimate debate about any of this: the efficacy of the vaccines, the safety of the vaccines, whatever. To be clear, there is no legitimate debate. We don’t have to discuss whether the Earth is flat and whether the Apollo mission has happened or not – vaccines work and are safe.

COVID-19 cases are rising once again even though we’ve had vaccine certificates in place for almost two months now. What would you say to those who might be wondering if they have really been an effective measure so far?

They’re absolutely effective. We currently have two measures that distinguish us from Europe, where cases are exploding, and also from parts of the US. Both measures don’t work ideally anymore in Ontario – people have become a bit less disciplined than before – but they sort of work. One is masking and the other one is vaccine certificates. And when you look at how crowded it can get in the small, intimate, Italian restaurant around the corner, I’m actually surprised by how well it has continued to work. Crowding relative to ventilation is the relevant quantity that is correlated with the risk of transmission, and considering the crowding I saw in some restaurants in Toronto, for example, I believe vaccine certificates actually worked surprisingly well.

You need a driving licence because it makes you safe and keeps others safe. That’s an apt analogy for vaccine certificates.

The difference between dropping masks and vaccine certificates as compared to maintaining both is day and night. We don’t have the explosive outbreaks that we see in Europe. Our effective reproduction number, Rt, is around 1.1. The effective reproduction number in the Netherlands and Denmark is at 1.4. So that’s basically the difference between 100 cases on average causing an additional 110 cases or 100 cases causing on average 140 cases. Right now, our doubling time (the time required for daily case numbers to double on average) is roughly five weeks. And the doubling time in the Netherlands and in Denmark is 10 days. That’s a big difference.

What do you say to those who argue that the rationale for vaccine certificates is undermined by the apparent waning of vaccine protection against infection and the ability of the vaccinated to spread the virus if they get a breakthrough infection?

This argument would only hold if the vaccine no longer protected against infection at all. But vaccines are still about 81 per cent effective in reducing the risk of infection, when they were about 87 to 88 per cent mid-August. That’s not a dramatic decrease, and it’s probably a combination of a bit of waning immunity and a large increase in risky behavior in the vaccinated as compared to before. We are now approaching the six-month mark, and we do not see much evidence of relevant waning yet. Around six, seven, eight months out, things might change, and booster shots will be required, but right now, we’re still looking fairly okay.

So we are still keeping the risk of infection in a high-risk setting lower through vaccine certificates. But even if there were outbreaks, it’s still better to only keep the fully vaccinated in the high-risk setting so that we keep those who are not fully vaccinated out of trouble. Even if only the vaccine effectiveness against hospital admission and ICU admissions was holding strong, this would speak in favour of vaccine certificates.

Some people argue that because vaccine certificates aim to increase vaccination by excluding the unvaccinated until they’re so inconvenienced that they get vaccinated, vaccine certificates effectively coerce the unvaccinated into undergoing medical treatment. This, the argument goes, impinges on their ability to provide free, informed consent to a medical procedure. How do you respond?  

I always refrain from emphasizing the nudging. I don’t think it’s particularly important in this province, where we have had really high vaccine uptake already, and we don’t see that the vaccine certificates have much of an impact on this. If it nudges somebody, then I see the positive aspect, which is that it protects this person.

As for those people who have experienced infection and still aren’t fully vaccinated, one compromise could be that if you have ever experienced infection, as documented by a positive PCR test, one vaccine dose could be considered equivalent to the full vaccination of somebody who hasn’t had an infection. But it’s the same principle: If you don’t have a driving license, sorry guy, you can’t drive. We took a more stringent approach in Ontario and require full vaccination for everybody; I’m perfectly fine with the approach we’re taking.

We shouldn’t emotionalize the discussion – it’s purely pragmatic.


Update: Jüni’s comment on vaccine misinformation was expanded for clarity.

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  • Phil Smith says:

    I think Dr. Juni explained his position on this issue very well. The driver’s license analogy is an interesting one. It

  • Rickk Sanchez says:

    Provocative and interesting findings that merit a deeper dive – however, nothing to see here, move along

    Abstract 10712: mRNA COVID Vaccines Dramatically Increase Endothelial Inflammatory Markers and ACS Risk as Measured by the PULS Cardiac Test: a Warning
    Steven R Gundry
    Originally published 08 Nov 2021Circulation. 2021;144:A10712
    “…..These changes resulted in an increase of the PULS score from 11% 5 yr ACS risk to 25% 5 yr ACS risk. At the time of this report, these changes persist for at least 2.5 months post second dose of vac. We conclude that the mRNA vacs dramatically increase inflammation on the endothelium and T cell infiltration of cardiac muscle and may account for the observations of increased thrombosis, cardiomyopathy, and other vascular events following vaccination…..”

  • Flora G Knight says:

    I do not understand the attitude of those who oppose vaccination against the COVID-19 as I am sure many of those individuals own pets and make sure that their pets are vaccinated against viruses such as Rabies or Heart Worm etc. They are very aware of the fact that their pets can die if they became infected with any of the viruses that are out there. The Rabies Vaccination is now compulsory following a Rabies Epidemic that killed many pets. I wonder what their argument would be if confronted about Vaccinating their pet?


Max Binks-Collier

Digital editor and staff writer

Max Binks-Collier is a journalist whose work has appeared in The Intercept, The Walrus, the Toronto Star, and Maisonneuve, among other outlets.


Peter Jüni


Dr. Peter Jüni is a general internist and epidemiologist, and the director of the Applied Health Research Centre at the Li Ka Shing Knowledge Institute of St. Michael’s Hospital. He holds a Tier 1 Canada Research Chair in Clinical Epidemiology of Chronic Diseases, and is a professor of medicine at the Department of Medicine and a professor of epidemiology at the Institute of Health Policy, Management and Evaluation at the University of Toronto. Peter is internationally renowned for his methodological work and for his clinical research on the management of cardiovascular and musculoskeletal disorders. He has contributed to over 500 papers, which have been cited more than 150,000 times. Since 2015 he has been recognized as a Highly Cited Researcher.

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