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.
I note that your example is from BBC News, a British source, saying the source is a legal article but neither quoting that article nor giving its legal citation. That is one reason that I think “immune to prosecution” is not the most frequently used construction.
In my thirty-five years practicing law in the USA, I have read and heard only “immune from prosecution”. It’s as if there’s a giant bulletproof window around the one “immune”.
In the context of an American president being immune from prosecution, the doctrine of “sovereign immunity” is related. This is a a legal doctrine dating from European monarchs, “sovereigns”. The president is not a sovereign, rather the nation is sovereign. Criminal prosecution and civil lawsuits against a sitting president would cripple his ability to work as the nation’s chief executive. That is the policy reason for sovereign immunity.
“Immune to” may be more frequent in a medical context. I have also heard of parents who were “immune to” children’s tantrums, in the sense of being able to ignore the tantrums.
As stated in one of the comments, prepositions can be flexible. Immune works with “to”, “from”, and “against”, and all are used in the USA.