What to do about vaccine hesitancy

It is a big problem and passports are not the answer

Welcome to Plugging the Gap (my email newsletter about Covid-19 and its economics). In case you don’t know me, I’m an economist and professor at the University of Toronto. I have written lots of books including, most recently, on Covid-19. You can follow me on Twitter (@joshgans) or subscribe to this email newsletter here. (I am also part of the CDL Rapid Screening Consortium. The views expressed here are my own and should not be taken as representing organisations I work for.)

“Forget it, if they don’t want it, they can suffer the consequences.” That was a statement from a normally empathetic colleague of mine when we heard about the latest data on how many people indicated that they were not likely to take a Covid-19 vaccine. The number was big in that survey — over 70%. At this point, I get it. It is easy to throw your hands up in despair. I mean, what else can you do?

But despair or frustration or blaming is a path to ruin here. It will help no one if we let the vaccine hesitancy issue be a source of conflict and stigma. But, equally, it appears that we are careening down that very path and, let’s face it, people haven’t got a great track record, especially these days, of avoiding it.

So I am going to take a pause today and try and set the vaccine hesitancy issue on a better footing. The bottom line, as with all of these things, is that there big shades of grey all around and real uncertainties. Nothing is black and white and so we have to be wary of any prescriptions based on a presumption of confidence and certainty. In other words, my audience today are those who are not hesitant about vaccines but have to deal with those who are.

Are vaccines a no-brainer?

I’m going to confess something to you. In September or October last year, I expressed to my colleagues that I wasn’t sure I would take a Covid vaccine. At least, I would not be lining up to be first. My reasoning was pretty simple. No vaccine had been developed in less than 4 years before and so how was it possible that a vaccine could be developed in under 12 months for a novel coronavirus while minimising safety and side-effect concerns? Up until that point, I had been expressing doubts as to whether a vaccine was our escape from this mess and so it was also consistent to have personal doubts should something appear. In particular, I did not trust the US government approval process at that stage although that wouldn’t apply to me regardless.

Needless to say, once we had results in November and the vaccines were very effective with few issues, my concerns evaporated quickly and I was sure I would be vaccinated as soon as I could be. And this applied to all of the vaccine candidates thusfar. As it happened, last week I became eligible for my first dose in Canada and received it promptly. I would recommend, without hesitation, that all do so. But I am very much in the weeds on this stuff so I don’t see myself as representative.

My point is that it is a reasonable position to be hesitant about vaccines. First, no vaccine has been approved for anything other than emergency use. It is not the same, years-long, process we are used to. Is that process useful or not? It is hard to know but deciding to reverse course during a crisis isn’t how you would make that call.

Second, while for most vaccines side effects turn up pretty quickly, there may be cases or situations where they only manifest themselves later. Only so much time has passed and the set of people who were part of trials skewed a certain way. They weren’t elderly and they weren’t people with certain pre-existing conditions. If you are a casual empiricist in your logic, that is a cause for concern. Indeed, the only way to assure yourselves differently is to understand the biological mechanisms at work in particular vaccine candidates or to trust someone who does.

Third, this isn’t a fun vaccine to take. Most people seem to experience some sort of immediate side-effect. I had a sore arm and about a half-day of feeling yuck. For others, it can be worse. Moreover, we have tried for years to educate people to be reflexively against just taking drugs — of any kind — and so there is an in-built issue for many.

Fourth, are the vaccines going to do the job? These vaccines are great — certainly by the standards of the flu vaccines. But they don’t seem as great by the standards of our childhood diseases. They probably are but there are re-infections. There were in the trials and there are now.

Twitter avatar for @EricTopolEric Topol @EricTopol
Reinfections among people getting placebo or vaccine who were seropositive at baseline —3% @pfizer trial
fda.gov/media/144245/d… 👇 —30% @Novavax South African trial 3.9% reinfection rate for those both seropositive and seronegative Further emphasizes immune escape of B.1.351 Image

That means that you are not 100% protected if you are vaccinated. That was always going to be the case. But it impacts on what people believe they are getting from being vaccinated. If I get vaccinated, it isn’t perfect and I end up getting grandma sick anyway, it isn’t a good outcome.

That said, the counterpoint here is the UK. They have vaccinated over 50 percent of their population and have seen deaths drop from global high levels in January to virtually nothing today. And that was mostly with a vaccine that was evaluated with lower efficacy and lower sterilising immunity. This suggests we can do more than we anticipated with less.

Fifth, then there are side effects. Blood clotting has been much discussed and I, for one, would be really annoyed if I took a vaccine and was hospitalised or died because of it. The risks are low. But there is a big difference in many peoples’ minds between low and zero.

All this is to say that people are going to have different private benefits and costs, perceived or otherwise, to getting vaccinated. If you focus just on current conspiracy theories (microchips) or past atrocities, you miss that basic point. To presume those preferences are illegitimate or unfounded is a mistake. We should, instead, take them as a given.

What drives vaccination?

In general, there are no benefits to being vaccinated. Yes, you read that right. And I mean both privately or socially. Of course, I haven’t finished the statement. In general, there are no benefits to being vaccinated, when there is very little chance of being exposed to a virus.

This is why we are not vaccinated for most tropical diseases unless we happen to travel to certain places. This is why no one, and I mean, no one, has been vaccinated for SARS-CoV-1 (the 2002 SARS coronavirus) despite it being more lethal and more infectious than SARS-CoV-2. There is a vaccine but by the time we had it, SARS had been wiped out so there wasn’t even a way to trial it properly.

All this is a roundabout way of saying that what drives vaccination is prevalence; both privately and socially. What is the likelihood of being infected by a virus? In some cases, that is protective insurance against an outbreak that may still occur — such as measles or even polio. But, of course, for the current pandemic, the risks are high are real … in most places.

Why are many clamouring to get vaccinated? The number one reason is that they fear contracting Covid-19 and its consequences right now. But, we know full well that the chances of getting Covid-19 are also a function of behaviour. If you are out and about or want to be, your chances are higher than if you are content to stay at home and do other things.

It is tempting, therefore, to frame someone’s vaccine decision in terms of once-off benefits and costs. But that isn’t really what we are talking about. We are talking about timing. How do we get more people to get vaccinated sooner?

This is a more complex calculus. Let’s consider a hesitant person who, believes that the costs of being vaccinated are high, and so there is no rush. If they were vaccinated today as opposed to, say, later in the year, they could either be less stressed about being infected in the near term and maybe feel comfortable taking more risks. If they are taking lots of risks anyway, because of, say, their job or because they are younger, then near-term risk mitigation is worth something. If not, then what is the rush.

But it is more complicated than just that. The vaccine is impacting that risk equation. In a rosy scenario, lots of people do get vaccinated today, prevalence drops way down and when you come to consider taking the vaccine in the fall, it doesn’t actually change your risk of infection much (as that is low) but the costs are the same. In other words, not getting vaccinated today, preserves an option not to get vaccinated tomorrow. That option is handed to you by people who are getting vaccinated today. It is a classic externality.

You can see where this is going, of course. The rosy scenario doesn’t play out if too many people think that same way. In that case, not enough are vaccinated and there is higher prevalence in the fall. So do you then relent and get vaccinated? It is unclear. You are facing in the fall, the same decision you faced now. Why would you decide differently?

You might decide differently because you have more information and because you are increasingly sick of mitigating risk without a vaccine. If that plays out then people get vaccinated but perhaps not as quickly as we would like. But it does happen until a point where it doesn’t matter whether the remainder is vaccinated or not. This may well be what is happening in the UK where well below herd immunity levels are being vaccinated but prevalence is falling anyway because those who aren’t vaccinated were mitigating risks regardless, and you end up with a situation where the pandemic evaporates. (That is a closed economy view and the virus can leak back in so I don’t believe that is a long-term solution at all).

According to this theory, therefore, vaccine hesitancy will actually rise as case numbers fall but, on the flip side, as people learn more they will believe the vaccine is safer. We have some data on this:

If you look at this, things are improving regarding hesitancy. The information effect is dominating. But my guess is the prevalence effect will be stronger in driving what people actually do. So beware of intentional surveys. It is likely that vaccinations will top off amongst more quickly than expected.

Do we want vaccination passports?

We are heading to a situation where many will be vaccinated but we will likely want others to be vaccinated as well. When there is a situation where the private incentives differ from the social incentives, the policy instruments first off the rank are ones that try to close that gap. I’m going to ignore the idea of paying people to be vaccinated as that is complex and it is unclear there is any reason it will work. Instead, I want to look at instruments that give the vaccinated additional rights — namely, vaccination passports.

To start, vaccination passports will be a thing; especially for international travel. But equally, I think that those who are hesitant are precisely those people unlikely to motivated by international travel. If they were, they would likely be less hesitant.

Instead, the question is what other things vaccination should allow you to do? Vaccination passports have a simple message: if you aren’t vaccinated, you are too risky to interact with so get vaccinated if you want to play with others. This makes sense. We do that for other vaccines — especially for children — and we do that for things such as being licensed to drive a car.

But, in this case, we have to consider carefully what the ends are. Unlike childhood vaccination, we aren’t thinking of long-term risk but, instead, of dealing with the current pandemic. Our goal is to get infections done as quickly as possible and keep them at a low level. This is important because, the theory of hesitation presented above, is driven by those very infections. In other words, what is being fed into the social calculus is not necessarily that different from the private calculus. They are working in the same direction.

Vaccine passports are designed to do one thing: if the reason you might be made less hesitant is that you want to play with others, a vaccine passport will give you that right. If you don’t get vaccinated, you won’t have that right. That makes them potentially attractive as a proposition.

This is important because the drive to get vaccinated quickly is the ability to go back to normal. If we, by contrast, didn’t allow the vaccinations to enjoy fewer restrictions, we wouldn’t get that effect. For this reason, many advocate ensuring that those who are vaccinated can actually enjoy the benefits of that.

That argument, however, is very different from a vaccine passport. The passport imposes a set of rules, regulations and verification on the process. You want to do that if that is the only way to relax restrictions for the vaccinated. When you do, however, you immediately create a divided society.

So what you need to ask is: will that divided society reduce vaccine hesitancy? On the one hand, if you think being on the other side is better than being on the side you are on, you will get vaccinated. But, on the other hand, who is on the ‘bad’ side? They are people who value the benefits of being on the other side less; most likely because they don’t see as much risk of contracting Covid. What’s more, the vaccine passport issue mitigates that risk anyhow.

You end up with two worlds — both of which potentially have lower prevalence. There is the vaccinated world where people play but are protected and so infections are low. Then there is the unvaccinated world where people don’t play but are protected by that and so infections are low.

And then there are the people trying to saddle both. For them, this is a complete mess. If they are vaccinated, perhaps they can juggle it. If they are not, there is disruption. For them, the vaccine passport system is likely to be very difficult and frustrating. Importantly, because, in this scenario, the pandemic starts to resolve, then that very resolution is going to put pressure on maintaining the system. It is very easy to see deep conflicts emerging.

Eyes on the prize

A vaccine passport says, “ok don’t get the vaccine but let me get on with it. You can stay in the pandemic world with all of the risks and costs of that.” But what the vaccinated really want is: “ok I am vaccinated. I don’t want to be hamstrung by restrictions because others have chosen not to be.” In other words, they don’t want a passport (which restricts others) but a license (which frees them).

But there is another way to get that license. Before I explain, I should preface what I am about to say here. I am about to posit a proposition that will be surprising and also that I am not 100% confident about. But it is the endpoint of the logic that I have persuing here and so I am going there.

Here goes: as we vaccinate more and prevalence falls, maybe we should remove all restrictions. On everybody. Vaccinated or not. And we should do it in the near term.

Now, that sounds like crazy. “Weren’t you the person who told us just the other day that in 2021-22 things might be worse because of vaccine hesitancy?” you may well ask. When there are a ton of cases later this year, a lack of restrictions will make all that much worse. This is true and, if that emerges, we may have to re-impose restrictions.

But, here is the thing. If we keep restrictions in, prevalence remains low and that, as I have said, can drive vaccine hesitancy. Instead, we want people to understand that prevalence may well not stay low. If you move to lift restrictions, then those who are hesitant may see that infections may surge again later on and so they will be at risk. In other words, the very commitment to restrictions can drive the hesitancy that is keeping them in place. The alternative is not to do that.

My point is that our focus should not be on share of people getting vaccinated but instead on the one thing we really care about: prevalence. And our policies regarding restrictions should be contingent on that and that alone. To be sure, if there are fewer people vaccinated, there is a greater outbreak risk. Vaccinated people are an investment in preventing that happening. But the policies and objectives are mixed together. That makes them hard to disentangle and target.

What I am not saying is just let it all rip. What I am saying is that a plan for reopening and relaxing of restrictions should be put in place contingent on prevalence. Those who are not vaccinated should understand that means that they will face increased risks along that plan unless they get vaccinated. The choice then is theirs of whether to bear that risk or engage in their own continued risk mitigation. That said, there is nothing in this plan that prevents all of the other tactics of influence and education being used to reduce vaccine hesitancy. Those are complementary.

However, I would also carve out exceptions. I think schools and colleges need different rules and strategies and mandates are likely appropriate. I think that we need to work out how to deal with health care environments, including, importantly, long-term care where we will worry the most about waning immunity from vaccines. But for much of the rest, second-guessing based on vaccine rates does not seem as favourable a path.

What I have in mind here is a plan like this: the government announces that if, on a certain date (say, October 1, 2021), prevalence is below X per 100,000 and is not rising at that point, then restrictions will be lifted. It will urge people to be vaccinated before that date and provide the means to do so. It will also provide other measures to help manage risk after that date (including rapid tests available for home use). The idea is that will focus attention and hopefully encourage more rapid vaccination choices. It will work if my assumptions that vaccination rates can be driven by expectations of prevalence and people can, to a large degree, manage their infection risk if not vaccinated. It is also based on assumptions regarding variants and whether vaccines protect against them. All or any of those assumptions may be wrong which is why this plan carries risk.


In summary, vaccine hesitancy is driven by Covid-19 risk which differs between people, depends on their preferences and is determined by the prevalence of the virus in the population. This means that as we deal with the pandemic, we increase the hesitancy problem.

Vaccine passports target the private motives to be vaccinated but not the factor driving the wedge between private and social incentives. What reduces that wedge is expectations of current and future prevalence with higher amounts reducing the wedge.

By planning to relax many restrictions as prevalence falls, this is a way of bringing the social and private incentives closer together with regard to vaccination. So that is what we should plan to do rather than relaxing once a certain amount of the population is vaccinated.