Will people actually get vaccinated against Covid-19? The city where I live, Paris, currently a pit of grey misery, hopes to start vaccinating the over-65s and other vulnerable groups in January. That is, if people will accept the vaccine. Scarily, 43-50 per cent of the French say in recent polls that they will probably or certainly refuse it. Many believe Big Pharma is in league with Emmanuel Macron to profit from a dangerous vaccine.

France was the most vaccine-sceptical of 140 countries surveyed by the Wellcome Trust in 2018. But “vaccine hesitancy” has been growing across the developed world. The proportion of self-avowed Covid-19 vaccine refuseniks in the US is similar to France. (People in poorer countries, who have often seen loved ones die of infectious disease, tend to wish for more access to vaccines.)

Antivax talk is worrying. However, it is only talk. Social media has made this the wordiest era in history. Sharing conspiracy theories online is excitingly subversive, making people feel they have taken the “red pill” and seen the truth. More telling, though, is their behaviour. In real life, when things get serious, almost everyone chooses vaccination. “If Covid-19 vaccines are found to be efficacious and safe and widely available, my guess is that a very large proportion of people will ultimately take them,” says Vish Viswanath of Harvard’s School of Public Health.