# vaccine

/ˌvækˈsin/ (US) · /væksˈiːn/ (UK)

Source: https://englishreference.com/word/vaccine
Updated: 2026-06-19

## Senses

### 1. medical treatment

noun · CEFR B1

a substance given to you, usually by a needle, to prevent a specific disease.

For teachers: a substance used to stimulate the production of antibodies and provide immunity against one or several diseases. Countable when referring to types or doses; uncountable as a general concept.

- The doctor gave the child a vaccine to protect her against the flu.
- Public health officials emphasized that widespread distribution of the vaccine was the most effective strategy for achieving herd immunity within the urban population.

### 2. computing

noun · CEFR C1 · Technical

a computer program that finds and removes viruses or malware.

For teachers: a software utility designed to detect, neutralize, or provide protection against computer viruses and other malicious code.

- You should install a digital vaccine to keep your laptop safe from hackers.
- The security suite includes a heuristic vaccine that identifies suspicious file behaviour even if the specific malware signature is not yet in the database.

### 3. to give a vaccine

verb · CEFR C2 · Archaic

to give someone a vaccine to protect them from a disease.

For teachers: to treat a person or animal with a vaccine to produce immunity. This verbal use is largely superseded by 'vaccinate' in modern standard English.

- In the old book, the doctor sought to vaccine the villagers against the pox.
- Historical records indicate that the physician attempted to vaccine the entire regiment before they embarked for the tropical colonies.

Usage: Takes a direct object; usually replaced by 'vaccinate' in contemporary prose.

Teaching tip: Modern speakers almost exclusively use 'vaccinate' as the verb. This form is likely to be encountered only in 19th-century texts.

## Examples

- This vaccine protects you from the flu.
- Public health officials recommend the new vaccine for children and older adults.
- The development of mRNA vaccines represented a significant technological leap, allowing for more rapid production cycles in response to emerging viral threats.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.