A recent news item reported :
... they are also concerned about his argument in a 2009 legal article that a sitting president should be immune to prosecution.
The OED states that the adjective 'immune' has three primary meanings :
free or clear (of or from)
wholly protected from
but then the OED states another meaning :
- having immunity to
I do not understand how the concept of 'to' arises.
'Immune' is to be exempt from, clear of, clear from, untouched by, totally protected from .......
How does the concept of 'to' arise ?
EDIT: Following a (sadly deleted ?) answer which also noted the usage of 'against' I am adding a link to the Ngram for 'immune to/immune from/immune against'. There seems to have been a difference between AmE and BrE in the early 20th century but nowadays there is agreement by both that 'to' is more common and 'against' is very rare.
I then added 'immunity to/immunity from/immunity against' and saw something interesting :
The wording 'immunity from' prevailed in the 19th century and then, I suppose, the concept of vaccination changed the way that immunity was regarded. The graph shows the changes.