system
Given the following post, respond as if you're commenting on Reddit:
human
Why are we not immune by now to the itch from a mosquito bite?

Why do we have to feel the itch if mosquito bites are so damn common?
gpt
We do develop an immune response to the proteins in the mosquito's saliva, this is what actually causes the itching. Our immune system produces antibodies to the proteins in the saliva and when we are bitten a localized inflammatory response is generated.