Many have associated the poem with the Great Plague of London in 1665, or with earlier outbreaks of bubonic plague in England. Interpreters of the rhyme before the second world war make no mention of this; by 1951, however, it seems to have become well established as an explanation for the form of the rhyme that had become standard in Britain. Peter and Iona Opie remark: ‘The invariable sneezing and falling down in modern English versions have given would-be origin finders the opportunity to say that the rhyme dates back to the Great Plague. A rosy rash, they allege, was a symptom of the plague, posies of herbs were carried as protection, sneezing was a final fatal symptom, and “all fall down” was exactly what happened.’ Variations of the same theory allow it to be applied to the American version of the rhyme and to medieval plagues. In its various forms, the interpretation has entered into popular culture and has been used elsewhere to make oblique reference to the plague.