'anti-contagion' is a modern English compound formed from the prefix 'anti-' (from Greek 'anti-' meaning 'against') and 'contagion' (from Latin 'contagio, contagiōnis' meaning 'a touching, contact, infection').

'contagion' came into English via Latin 'contagionem' and Old French 'contagion' meaning 'a touching, infection'; the prefix 'anti-' (Greek) was attached in modern English to form compounds like 'anti-contagion' in public-health and political usage, especially in the 19th–21st centuries.

The elements originally referred to 'against' and 'touching/infection'; combined, the compound came to mean specifically 'opposed to or preventing transmission of disease', used especially for policies and measures.