We probably agree, don't we, that the media are bad at medicine. For example, on a recent edition of the Victoria Derbyshire phone-in show on BBC Radio 5 Live, which likes to bill itself as “the nation's conversation,” the country was discussing the proposal to inoculate children against chickenpox.

A woman who called in was against the idea, warning that, having been encouraged to catch the virus from her sister in what used to be parental practice, she had gone on to develop meningitis and septicaemia and been given the last rites. But despite this she had later developed chickenpox for a second time in adulthood. When Derbyshire, with the fast radar for barminess that becomes natural to phone-in hosts, expressed surprise at this medical history, the caller explained that the first occasion had involved an “inner” symptomless virus but that she had later suffered an “outer” bout.

Derbyshire ended the conversation as quickly as if there were botulinum bacteria on the receiver and then, in the way of her programme, read out two contrasting …