Many readers will, like me, have been relieved to see infection rates in the UK falling in recent days. So the news that the government is to waive quarantine requirements for “high value” –  it is hard to think of a term better calculated to cause offence – travellers will not be universally taken as good news.  As far as I am aware, the virus is no  respecter of status, social or business.

The inevitable result will be that infection rates, and deaths, will once again start to rise. It was, after all, travellers from abroad, who brought the virus here in the first place.

In honour of the prime minister the resulting pattern – veering up and down the page like a drunkard on a beach –  might aptly  be called the J-curve.