IPA: /ˌɪmjunəˈlɒdʒɪkli/
KK: /ɪˌmjunəˈlɑɡɪkli/
In a way that relates to the immune system and its functions.
The vaccine works immunologically to protect against diseases.
Immunologically → It is formed from "immunis" (from Latin, meaning exempt or free from) and "-logy" (from Greek "logia", meaning study of). The word "immunologically" refers to the study of the immune system and its functions, particularly in relation to immunity.
Think of being 'exempt' or 'free from' disease ('immunis') and the study of that ('-logy'). This helps you remember that immunologically relates to the study of immunity.