protected against a particular disease by particular substances in the blood

Most people who've had chickenpox once are immune to it for the rest of their lives. 大多数出过水痘的人终生都对此病具有免疫力。

He seems to be immune to colds - he just never gets them. 他好像对感冒具有免疫力——他从不感冒。

not affected or upset by a particular type of behaviour or emotion

The press had criticized her so often that in the end she had become immune (to it). 新闻界如此频繁地批评她，以至于到最后她都（对此）变得无动于衷了。

not able to be punished or damaged by something

Journalists, he insisted, must be immune (= protected) from prosecution. 他坚持新闻记者必须免受起诉。