In a first edition of Edward Jenner’s 1798 book Vaccination Against Smallpox, where the English physician described the science behind the vaccine that would eventually eradicate the disease, a sceptical reader had scrawled: “Bah Humbug!!”

Vaccine hesitancy is nothing new. It predates the internet’s conspiracy-amplifying powers. And it certainly predates the technical, regulatory and political blunders that have undermined confidence in the Oxford/AstraZeneca Covid-19 vaccine in Europe and elsewhere. Mistrust more than misunderstanding stokes vaccine fear. The idea that confidence can be restored through “education” misses what we all know about trust: it is hard to gain and easy to lose...