“They need to grow up”. The Prime Minister’s response this week to a question on anti-vaccine conspiracy theorists. If only it were that simple. If only the malign and dangerous messages spread by anti-vaxxers were mere immaturity. They are much more than that.

Scepticism about new medicines or new treatments, especially those targeted at the whole population, has a centuries-old lineage. More than 200 years ago, the man who gave us the very word “vaccination” was ridiculed and his work undermined by the David Ikes, Piers Corbyns and Kanye Wests of his day. Edward Jenner’s cowpox treatment for smallpox was rejected by his critics on grounds ranging from religious belief and superstition to professional jealousy.

Nothing new under the sun – except sometimes there is. Vaccination, it turns out, is one of the greatest human achievements in global health. An everyday miracle. Something new under the sun. Jenner couldn’t know it but it would be another two centuries before the disease he called “the speckled monster” – which had co-existed with human beings for thousands of years, killing a third of those it infects – would be eradicated totally. Other infectious diseases are still on that journey but all the while lives are being saved and futures secured.