The Grammarphobia Blog

Immune response

Q: My mom says that I’m “immune from” the mumps since I had the disease as a child. And she ought to know! But I’m not sure she knows the correct preposition to use with “immune”? Shouldn’t she say I’m “immune to” the mumps?

A: I’m on your side. Medically speaking, somebody is “immune to” a disease or has “immunity to” it.

In its entry for “immune,” Merriam-Webster’s Collegiate Dictionary (11th ed.) uses “immune from” in the sense of exempt or protected (“immune from further taxation … immune from arrest”), but “immune to” in the sense of not susceptible or responsive, as well as in the sense of medically resistant (“immune to all pleas … immune to diphtheria”).

The American Heritage Dictionary of the English Language (4th ed.) appears to agree. The examples it gives in its entry for “immune” use the preposition “from” in the sense of exempt, or not subject to an obligation: “immune from taxation; immune from criminal prosecution.” But it uses “to” in the sense of not susceptible or responsive (“immune to persuasion”). There’s no example given for medical immunity, but the definition uses the phrase “resistance to infection.”

The New Fowler’s Modern English Usage, edited by R.W. Burchfield, says a person is “immune to an infection” but “immune from some undesirable factor or circumstance.” Burchfield adds, however, that “the division is not clear-cut; in some contexts from is idiomatically used in type (a) and to in type (b).”

In fact the Oxford English Dictionary has many examples of “immune to” and “immune from” that don’t follow the predictable pattern. Your mom, for instance, could reasonably argue that she says “immune from” because she means that you’re “protected from” the mumps rather than “resistant to” the mumps.

Here’s an interesting aside. “Immunity” is the original word, dating from the 1380s. “Immune” is the latecomer, a back-formation dating from the mid-1400s. Also, the sense of “exempt from” preceded the medical meaning (“resistant to”). That may explain some people’s belief that “immune from” is the preferred form.

Anyway, this is an issue of usage or idiom rather than grammar. It all reminds me of a particular irritant of mine—folks who say so-and-so “died from cancer” rather than “died of cancer.”

We wouldn’t have problems like these, of course, if English weren’t so rich in prepositions!

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