Vaccination and me

Face it: Most of us are lousy at accurately assessing risks and benefits.

We buy lottery tickets hoping to win millions even though the chances of winning are one in several million. Even though we know in our rational mind that this is the case, we like to believe we might be that lucky one. Some of us even know million-dollar lottery winners which makes the chances of winning seem even greater somehow.

The same is true when it comes to our health and how we perceive COVID-19 risks and the benefits of vaccination against disease. What we know to be true and how we choose to act don’t always coincide.

Understanding the true risk of contracting a disease or having a side effect from a treatment should be easy to do. Research provides numbers based on good scientific evidence. But doctors have long understood that communicating risk in a way we can truly comprehend is not easy because emotions and our own personal perspective and experience often come into play.

This can become a real issue when physicians and scientists try to convey the risks of contracting COVID-19 and the unquestionable benefits of approved COVID-19 vaccines. And remember, while these vaccines undoubtedly provide protection against COVID-19 or reduce the severity of illness if you do become infected, the reality is that no vaccine is 100% safe and effective.

An Australian article dealing specifically with assessing the risks and benefits of COVID-19 vaccines notes that we have ways of thinking about risks and benefits that can affect our ability to make the right choice. One of these is the ease in choosing to do nothing. As the article states: “Sometimes people want to avoid a sense of regret (‘what if I make the wrong choice?’) and are more willing to accept an outcome if it’s the result of us doing nothing (‘if I avoid the vaccine, I know I might catch COVID-19’), rather than a result of taking action (‘if I get the vaccine, I might have a severe side effect such as blood clots’). We are extra-cautious if we think there’s a lot of uncertainty involved.”

It doesn’t help that when the side effects from a vaccine are published, the risk is often portrayed as being 1 in 100 or 1 in 1000 or whatever the number is. Studies have shown when put this way, you tend to identify with the 1 and so overamplify the risk.

Many people are also more risk adverse to new or innovative technologies such as the mRNA COVID-19 vaccines produced by Pfizer BioNTech and Moderna especially as the false news machine promoted the lie that these vaccines can alter your DNA. What is not often pointed out is the amount and years of existing research that went into developing this new approach to vaccination. As noted on the Canadian Institutes for Health Research website “the science behind the COVID-19 vaccines was not rushed. If anything, the story behind them—and the decades of research within that story—is remarkable.” This approach to vaccination has proven so successful that it is now being tested to immunize against everything from seasonal flu to the Zika virus.

Risk comparisons can be useful when assessing the risk of adverse effects from COVID-19 vaccines. When it was revealed that the risk of blood clots was relevant for the AstraZeneca and Johnson and Johnson vaccines, doctors were quick to point out that you were more likely to develop a blood clot from COVID-19 itself, than from the vaccine. Helpful explanations were also made that the risk of developing a blood clot as a cause from the vaccine was far less than from taking birth control pills or, as a Toronto physician argued, was the equivalent to the risk of being hit by a car and dying in Toronto in a given year.

If you have trouble picturing these numbers in your head, seeing the risk portrayed in graphic form can often help to make more sense of numbers.

For example, the chart below shows the probability of developing symptoms from COVID-19 (breakthrough infections) by fully vaccinated individuals:

Another chart from San Diego in the US compares the number of hospitalizations from COVID-19 between those who have been fully vaccinated and those who are not:

We can easily perceive the risks of COVID-19 vaccination as being greater than they are because this is what we see portrayed in the news. It is well worth remembering that journalists are interested in the unusual and the surprising.

You will never see stories about Mrs. X receiving two doses of a COVID-19 vaccine and not having any side effects and not getting COVID-19. That’s because this is a normal and expected occurrence and so not seen as being interesting or “newsworthy”. However, rare side effects from vaccination or serious illness or even death among those who have been vaccinated are “news” and receive prominent attention just because they are so unusual.

Correctly assessing risk and benefit can be even more challenging at this time as more of the population is being fully vaccinated against COVID-19, yet we are seeing what is being called a fourth wave of infections due to the delta variant of COVID-19.

It is not just genuine news stories who can feed incorrect perceptions of COVID-19. Social media are rife with incorrect and inaccurate information about COVID-19 vaccines and possible side effects, deliberately spread by those trying to mislead people or create opposition to medical authorities. For example, there is absolutely no evidence that vaccination can lead to infertility, yet this is one of several memes that keeps resurfacing on social media no matter how effectively it is debunked by legitimate scientists.

Unfortunately, some people genuinely believe these false statements and spread them in the hope of warning others. However, the initial statement is often generated with a malicious intent.

Fighting misinformation has been identified as one of the main challenges facing those trying to control and eradicate COVID-19 and increase vaccination rates. For someone just trying to do the right thing to protect themselves and their loved ones the approach should be to critically evaluate everything you see about COVID-19 and vaccination and use information and advice coming from trusted sources (e.g. the WHO, the CDC, the Public Health Agency of Canada) and supported by solid scientific evidence.

Sure, if you don’t buy a lottery ticket you can’t win. But if you don’t get fully vaccinated against COVID-19 you risk losing a lot. And as the 4^th wave spreads, the odds aren’t in your favor.