Last weekend, I took part in a family Zoom chat with a dozen of my cousins who live around the world. In the course of conversation, I idly asked how many would have a Covid-19 vaccine if one became available (a hypothetical question at the time, as the cheering results of the Pfizer-BioNTech drug trial had not yet emerged).

The geographical split was striking. My cousins who live in Ireland would have a vaccine; they trust scientists. So would most (but not all) of those based in England. A cousin in Australia sounded shocked that anyone would even need to ask the question. But the US-based contingent muttered “probably not” or “I’ll wait and see”, echoing the reactions of most of my East Coast-based friends over recent days.

While this is merely an anecdotal tale, it reinforces what we see in surveys. Between May and September this year, the proportion of US adults who said they were definitely willing to have a Covid-19 vaccine fell from 72 per cent to 51 per cent, according to the Pew Research Center.