There should be no doubt about it: Covid-19 vaccines are saving lives.
Consider some recent statistics from the UK. In a study tracking more than 200,000 people, nearly every single participant had developed antibodies against the virus within two weeks of their second dose. And despite initial worries that the current vaccines may be less effective against the Delta variant, analyses suggest that both the AstraZeneca and the Pfizer-BioNTech jabs reduce hospitalisation rates by 92-96%. As many health practitioners have repeated, the risks of severe side effects from a vaccine are tiny in comparison to the risk of the disease itself.
Yet 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.
The 5Cs
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."
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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 mind. "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.
Fear of needles is a leading reason why many are reluctant to take the vaccine, research suggests (Credit: Jasmine Merdan/Getty Images)
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 behaviour. 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