'anatoxin' originates from German, specifically the word 'Anatoxin', where 'ana-' meant 'up, again' and 'Toxin' meant 'poison'.

'Anatoxin' was adopted into English from the German word 'Anatoxin' in the early 20th century, and eventually became the modern English word 'anatoxin'.

Initially, it meant 'a toxin that has been rendered harmless', and this meaning has remained the same in modern usage.