Vaccine hesitancy and the limits of empiricism

To understand popular distrust of vaccines we need to look to Voltaire and the rejection of Enlightenment science.

In 1733, four years after his return from England, where he’d been exiled for humiliating a French aristocrat, Voltaire wrote a series of philosophical letters describing England’s system of government and its embrace of free trade and religious tolerance. Written in a deliberately faux-naïf style, Voltaire’s Letters Regarding the English Nation appear, at first glance, to be a satire of England’s peculiar customs. The English are “fools and madmen,” Voltaire begins his eleventh letter, On Smallpox Inoculation:

“Fools, because they give their children the smallpox to prevent their catching it; and madmen, because they wantonly communicate a certain and dreadful distemper to their children, merely to prevent an uncertain evil.”

Voltaire was not describing vaccination as we know it today but its precursor, variolation, whereby practitioners would take a small amount of pus from a lesion on a smallpox victim and introduce it under another person’s skin in the hope of inducing an immune response. However, on closer reading, it’s clear that far from being an anti-vaxxer, Voltaire was a supporter of variolation and his real targets were opponents of the new empirical scientific methods associated with John Locke and Robert Boyle. Describing smallpox as a “cruel disorder” that kills one in three of those infected and leaves survivors “horribly disfigured,” Voltaire asks rhetorically: “Aren’t the French fond of life? Do their women not care about their beauty?”

Female patient with smallpox in the vesicular stage. Source: Wellcome Images.

Voltaire was right to be concerned by French resistance to the procedure. In 1723, smallpox killed 20,000 Parisians, including Voltaire’s close friend Génonville (Voltaire also contracted the disease but, after being copiously bled by a doctor, miraculously survived). By contrast, Voltaire explains, in England and countries such as Turkey where variolation had been widely adopted, no one inoculated against smallpox had “ever [been] known to die” and “no one is marked” by the disease.

Were he alive today, Voltaire would no doubt be appalled to learn that despite 300 years of scientific progress, France remains the most vaccine-hesitant nation in the world, with one in three French people believing that vaccines are unsafe and nearly half saying they would turn down a coronavirus jab, compared to 21 percent in the UK.

On the other hand, he would be encouraged to learn that, thanks to President Emmanuel Macron’s decision in the summer of 2021 to issue vaccine passes, with proof of a second shot required to visit a restaurant, gym, concert hall, or sporting event, 80 percent of the French population is now double-jabbed. Yet in Britain, where the government has so far resisted mandatory vaccines and been reluctant to adopt strict Covid-19 control measures, immunization rates are stuck at around 70 percent.

Certainly, last autumn, I felt far safer visiting Paris—where I was required to mask up and present my vaccine pass at the Eurostar check-in desk at St. Pancras International and again at a brasserie on the Île Saint-Louis—than I did living in London, where, masks are no longer required and, to judge by the conversations in the locker room of my local gym, many young people are vaccine-hesitant.

There are many theories as to why, despite the strides made in vaccinology, the populations of mature Western democracies remain resistant to vaccination.