What does immunize mean?
Immunize means to protect someone or something from disease by giving a vaccine or by otherwise establishing immunity. In its most common use, it refers to vaccination: clinics and public-health programs immunize children, patients, and populations against illnesses such as measles, polio, and influenza. The word can also have a figurative meaning, as when experience immunizes a person against misleading claims or repeated failures. Its use is especially prominent in medicine and public health, where immunization programs are designed to reduce transmission and prevent serious illness. Although vaccination is the clearest method of immunization, the word can also refer to immunity produced by other biological or medical processes. The concept has become one of the foundations of preventive medicine, allowing communities to limit the spread of infectious diseases through widespread, organized protection.
To protect a person or animal against a disease by administering a vaccine or by otherwise establishing immunity.
"Health workers immunized thousands of residents during the outbreak."
Commonly used with against, followed by a disease or infection.
To make someone or something resistant to harmful or adverse influences.
"Repeated setbacks immunized the company against overly optimistic forecasts."
This figurative sense is less common than the medical sense but is idiomatic in both formal and informal writing.
Immunization transformed many once-fatal diseases into preventable inconveniences—and helped create the modern expectation that medicine should shield us before illness strikes.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does immunize come from?
Immunize derives from the Latin immunis, meaning “free from” or “exempt from,” especially from a burden or obligation. The English adjective immune and the related nouns immunity and immunology developed from the same Latin root. In modern usage, immunize became associated with the deliberate administration of vaccines to create protection against infectious disease, especially during the 19th and 20th centuries.
Related word forms
How immunize is actually used
The spelling is normally immunize in American English and immunise in British English. The phrase immunize someone against something is standard; the word often carries a formal, public-health tone, though it can also be used figuratively.
Easily confused with immunize
Immunize is the general modern term for giving a vaccine, while inoculate can refer more broadly to introducing a substance into an organism, although it is also commonly used as a synonym for vaccinate.