Where did ‘herd immunity’ come from?
‘It was the pyres,’ said my husband. He meant the effect of television pictures of cattle, hooves silhouetted against the sky, burnt during the foot-and-mouth outbreak of 2001. It was eradicated by culling six million beasts, not by vaccination producing herd immunity. In Shropshire, stone memorials survive to the outbreak of rinderpest (like Covid-19 a
