What Factors Contribute To Vaccine Hesitancy?
A sizeable number of people are still reluctant to get the shots. According to a recent report by the International Monetary Fund, that ranges from around 10-20% of people in the UK to around 50% in Japan and 60% in France.
The result is becoming something of a culture war on social media, with many online commentators claiming that the vaccine hesitant are simply ignorant or selfish.
But psychologists who specialise in medical decision-making argue these choices are often the result of many complicating factors that need to be addressed sensitively, if we are to have any hope of reaching population-level immunity.
First, some distinctions. While it is tempting to assume that anyone who refuses a vaccine holds the same beliefs, the fears of most vaccine hesitant people should not be confused with the bizarre theories of staunch anti-vaxxers.
“They’re very vocal, and they have a strong presence offline and online,” says Mohammad Razai at the Population Health Research Institute, St George’s, University of London, who has written about the various psychological and social factors that can influence people’s decision-making around vaccines. “But they’re a very small minority.”
The vast majority of vaccine-hesitant people do not have a political agenda and are not committed to an anti-scientific cause: they are simply undecided about their choice to take the injection.
The good news is that many people who were initially hesitant are changing their minds. “But even a delay is considered a threat to health because viral infections spread very quickly,” says Razai.
This would have been problematic if we were still dealing with the older variants of the virus, but the higher transmissibility of the new Delta variant has increased the urgency of reaching as many people as quickly as possible.
Fortunately, scientists began studying vaccine hesitancy long before Sars-Cov-2 was first identified in Wuhan in December 2019, and they have explored various models which attempt to capture the differences in people’s health behavior.
One of the most promising is known as the 5Cs model, which considers the following psychological factors:
Confidence: the person’s trust in the vaccines efficacy and safety, the health services offering them, and the policy makers deciding on their rollout
Complacency: whether or not the person considers the disease itself to be a serious risk to their health
Calculation: the individual’s engagement in extensive information searching to weigh up the costs and benefits
Constraints (or convenience): how easy it is for the person in question to access the vaccine
Collective responsibility: the willingness to protect others from infection, through one’s own vaccination
In 2018, Cornelia Betsch at the University of Erfurt in Germany and colleagues asked participants to rate a series of statements that measured each of the 5Cs, and then compared the results with their actual uptake of relevant procedures, such as the influenza or the HPV vaccine.
Sure enough, they found that the 5Cs could explain a large amount of the variation in people’s decisions, and consistently outperformed many other potential predictors – such as questionnaires that focused more exclusively on issues of trust without considering the other factors.