A way out of the risk-benefit labyrinth

In the past week, many European countries halted vaccinations with AstraZeneca’s COVID-19 vaccine after rare cases of thromboses.  

How do we weigh the risk for the individual who is being vaccinated against the societal risk of the pandemic and its by-products?  

Individual risk perception – where hunches trump numbers  

If we want to do more than just sit at home and wait for it all to end, we must accept a certain level of danger in our lives. We define our comfort zones, deciding how risky our professions, free time activities and lifestyles can be.

When making those decisions, individual perception of risk often differs significantly from the actual probability of the risky event occurring.

On the one hand, our brains bias us positively towards occupations that are fun and/ or addictive. For activities that bring (short-term) pleasure, like sun-bathing, drinking, smoking, reckless driving, unhealthy eating, and frying our brains with hours of social media doom scrolling – we are much more willing to accept the risk of short or long-term negative effects.

On the other hand, human brains don’t seem to be made for understanding probabilities in more than a metaphysical way. If they were, no one would EVER play the lottery.

But there is always the hope to be THE ONE. And in that sense, our brains can actually process the logic of probabilities. Because being the one to crack the jackpot isn’t impossible, it’s just extremely unlikely.  

It works the same way for bad events. The fear of flying appears unreasonable, when comparing the actual risk of a plane crash to the risk of being in a car, with the much more real danger of fatal accidents.

Assessing risk-benefit for medications – numbers and psychology

Most people take some kind of medication for treating acute symptoms such as headaches, chronic conditions such as high blood pressure, or in the worst case, life-threatening diseases such as cancer.

What is an acceptable risk profile for a drug?

Depends on its benefit.

Medical agencies such as the American FDA or the European EMA weigh the good a medication does for patients against the potential harm it might cause before allowing it onto the market. The acceptable risk of side-effects should obviously be much higher for a drug that treats a fatal disease than for one that treats something minor like a headache.

While this logic of risk vs. benefit makes sense on paper, human psychology seems to deviate. For example, many people would be willing to accept quite severe side-effects for weight loss medication or acne treatments. The severity of a condition, and perceived benefit of a treatment are different for everyone, and determine the risk threshold.

The invisible danger – assessing risks of preventative measures

Our risk threshold is much lower when it comes to preventative treatments, medications, or vaccines we take to avoid getting sick. Here, we always have to weigh the immediate risk (potential side-effect of the preventative treatment) against the risk of getting ill (maybe) in some unknown future.

The risk of contracting COVID-19 is difficult to assess and can be calculated based on where we live, how many people we meet, where we meet them and so on. For example, for my location the probability that any person, I meet has COVID-19 is currently 3%, with the risk of catching the disease depending on the type of interaction (inside vs. outside, long vs. short, close vs. distant, quiet vs. loud singing etc.).

The risk of serious complications or even death differs significantly between age groups. While in the overall population in Germany 3%, of people who got COVID-19 have died with the disease, this percentage is up to a 100-fold lower in younger patients.

The AstraZeneca vaccine has had bad press since its bumpy start. After the initially published efficacy was lower than that of the contestants from BioNTech/ Pfizer and Moderna, and the way the study was done and data published felt (honestly) a bit messy, with muddled-up dosing regimens, unpublished cohorts and not enough elderly patients in the initial study to draw conclusions for those high-risk patients. While the efficacy is currently estimated at slightly above 60%, the vaccine offers a reassuring 100% protection against severe disease, hospitalization and death.

But the recent discussion isn’t so much about the efficacy of the vaccine than about potential safety concerns, namely blood clots (thrombotic events). The general thrombosis risk is LOWER than in the general population, and for pulmonary embolism definitely lower than in COVID-19 patients.

But with the AstraZeneca vaccine, there might be a higher risk of specific brain thromboses - cerebrovascular venous and sinus thrombosis. That said, those thrombosis occurred in 25 out of 20 million vaccinated people in Europe – a chance of slightly higher than one in a million, and the causal link between the vaccine and the thrombosis is not (yet?) established. On the 18th of March, the EMA clearly stated that the benefits of the AstraZeneca vaccine outweigh the risks of those rare events.

That recommendation notwithstanding, each person is allowed to decide on the risk they are willing to take for themselves. In our society, individual risk trumps society risk.

BUT, if we choose against vaccination, which is and should be anyone’s right, we influence not only ourselves. We make it easier for the virus to spread. The higher the numbers, the higher the chance for ourselves and others to contract the diseases, to die from it or to develop long term disability. And the harm the pandemic causes goes beyond the direct effects of COVID-19. Measures, such as lockdowns and school closure are a severe burden for mental health, with depression rates in adults doubled in comparison to pre-Pandemic levels.

Risk tradeoffs are never easy, not for the individual and not for society as a whole. I am glad to live in a society that respects my own, often irrational perception of risk, that allows me to get sunburns, and hangovers, and spend thousands on lottery tickets that never win…

But when it comes to vaccination, I feel that the individual and societal risks are basically aligned – the sooner the pandemic is over, the better it will be for everyone.

If you ask me – I would take a shot of AstraZeneca (or any of the other vaccines) in a heartbeat as soon as anyone offers. In the meantime, I’m patiently waiting with my sleeve rolled up.

The unpopular solution – vaccine hopes, fears and denials

Within the last week we’ve experienced a sprint of good news – with press releases showing vaccine efficacy above 90% toppling over one another as BioNTech/Pfizer and Moderna race their vaccines towards the finish line.

The efficacy found in those trials is spectacularly higher than the set approval target of 50% from the United States Food and Drug Administration and much higher than effectiveness of vaccines against seasonal flu, which need to be “remade” each year, due to the influenza virus’ high mutation rate.

Under normal circumstances  - meaning “old normal” - vaccine development takes more than 10 years even in a best case scenario. The companies that are now submitting their data to regulators did it in less than a year.

There may be differences in safety, temperature stability and associations to Dolly Parton (the latter being a decisive factor for my own humble favoritism). But contrary to the usual drug to market contest, where the first drug over the finish line gains a (sometime massive) advantage, this vaccine race knows only winners. The demands for COVID-19 vaccine are so high that there is space for many contestants to take the crown.

How does the public react to that hopeful piece of news?

For people like me, the news of a potentially effective and safe vaccine mean a relief that equals a huge suffocating weight (huge, like for example the sum of all pandemic weight gain in my city of 4 million people) falling off my chest. An effective vaccine seems to be the ONLY realistic hope of ending the pandemic soon and without even more dramatic casualties and economic damage, than we’re already experiencing.

There is a second group of people, the indifferent bunch, who don’t seem too enthusiastic about the vaccine news, thinking – SO WHAT? They’d seen the development of an effective vaccine as a given and feel nothing but a mild disappointment that the looming vaccine doesn’t end the pandemic in an instant and that it may still take at least a year or more for the existence of vaccines to translate into a return to normal – in this case “old normal” or a better version of “new normal” .

Then there is a third group of people: those who don’t want to be vaccinated. Some of those people have concerns that vaccination might do more harm to one’s health than it would do good. Others see vaccination as the work of the devil, as a big ploy of evil elites, who try enslaving the ignorant population, as a money-making scheme by the pharma industry, who hide vaccines’ dangerous side-effects, from autism to mind control via microchips (I guess I don’t have to spell out that neither autism nor microchip-mind control are side effects of vaccines, o wait, now I’m spelling it out anyways), and that as a final coup, those vaccines will be delivered by genetically modified mosquitoes (which, I must admit might actually work in the future) .

The antivaccination movement hasn’t been born amid the pandemic but as other anti-science movements, is gaining momentum as the pandemic tide washes over us, leaving people confused and desperate for alternative explanations – explanations which deviate from the general tenor of “This sucks but it might be over eventually if we all grit our teeth and push through”.

 

Underlying vaccination hesitancy is a deep-set human refusal to acknowledge bad things might befall us, or our children. It’s too abstract to imagine the threat from diseases, which have been virtually eradicated by vaccination, or in the case of COVID-19, too abstract to connect the pictures on the television of overrun hospitals and of exponential growth curves to our own lives. We feel young, and healthy and above all invincible – even if we never truly are.

And then there is the believe in alternative truths – COVID19 is a hoax and scientists are idiots in league with dark powers... The ability to hold those different theories in one’s mind is a complex feat worthy of Orwell’s doublethink (though it might even be triplethink here): 1) believing in the impotence of science, 2)  granting scientists with the ability to bring about the scientific miracles worthy of a dystopian sci-fi thriller (microchip-mosquito-mind-control) 3) believing that the protection from those high-tech threats lies in methods worthy of a medieval witch craze, like wrapping your head in metallic foil or wearing protective gemstone charms.

While those ideas appear as enjoyably absurd as a Monty Pythons sketch, the spillover of the crazy ideas into mainstream thinking endangers the population and the economy. Polls say that only ~50-65% of people want to be vaccinated against COVID19 in the US, UK, Germany.

SO WHAT? say the indifferent (because that’s what they always say) ...

If those people don’t want to get vaccinated, more vaccine left for the smart ones who’ll get their shot at the shot earlier. BUT (and that one’s a clear all caps) BUT we need enough people vaccinated to achieve herd immunity and hopefully make the virus disappear. And the people who refuse vaccination, and who will likely also refuse other security measures like wearing masks and keeping social distance, will still fall ill with COVID-19, will still need treatment in hospitals and take up space in ICUs. It’s not an option to deny them treatment for their own stupidity. Punishing stupidity is not a tempting idea as all of us are prone to endanger our health with some kind of stupid behavior, from unhealthy lifestyle choices, from fatty food to dangerous sports.

No, punishing stupidity is not and shouldn’t be an option, and yet, we have to live with the reality that the stupidity of some has the power to punish the rest of society with their antivaccination stance.