IPA: /prəˈfɪl.æk.sɪs/
KK: /prəˈfɪl.æk.sɪs/
A method or treatment used to prevent disease or protect health.
Vaccination is a common form of prophylaxis against infectious diseases.
Prophylaxis → It is formed from "pro-" (meaning before) and "phylaxis" (from Greek "phulaktikos", meaning to guard or protect). The word refers to measures taken to prevent disease or protect against something before it occurs.
Think of taking precautions 'before' ('pro-') to 'guard' ('phylaxis') against illness — that's what prophylaxis means.