What does immunized mean?
“Immunized” is the past tense and past participle of “immunize,” meaning to give someone protection against a disease by causing their immune system to develop the ability to recognize and fight it. Most commonly, the word refers to vaccination against an infectious disease: a person may be immunized against measles, influenza, or tetanus. It can also be used more broadly to describe protection from a harmful influence, as in a plan that is immunized against financial risk. The word is especially common in medical, public-health, and educational contexts. Its use implies deliberate preparation rather than accidental resistance, while the construction “immunized against” is the standard way to identify the disease or threat being addressed.
To make someone immune to a disease, especially by vaccination.
"The nurse was immunized against hepatitis B."
Usually followed by “against,” naming the disease or condition.
To protect someone or something from a harmful or threatening influence.
"The agreement was immunized against sudden changes in the market."
This figurative use is less common than the medical sense.
Immunization does more than prepare the body for a particular disease: it trains the immune system to recognize and fight a threat on later exposure.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does immunized come from?
The word “immunized” derives from “immunize,” which was formed from “immune” and the suffix “-ize.” “Immune” comes from Latin immunis, meaning “free from” or “exempt,” and ultimately relates to the idea of being protected from a burden or threat. In the development of modern medical usage, “immunize” came to mean specifically making a person immune to a disease, especially by vaccination. Related English forms include “immunity,” “immunology,” and “immunological.”
Related word forms
How immunized is actually used
In medical contexts, “immunized against” is the usual construction. The word is relatively formal and is most common in public-health and educational writing.