# prophylaxis

/pɹˌɒfɪlˈæksɪs/ (UK) · CEFR C2 · Noun

Source: https://englishreference.com/word/prophylaxis
Updated: 2026-10-19

## Definition

treatment or action that stops a disease before it starts, such as a vaccine or preventive medicine.

For teachers: preventive medical treatment or public-health measures taken to avert disease or infection before onset. Contrasted with therapy, which treats disease after it appears.

## Examples

- Vaccines provide effective prophylaxis against many diseases.
- The dentist recommends regular cleaning for prophylaxis against gum disease and tooth decay.
- Public health officials debated whether widespread antibiotic prophylaxis would prevent an outbreak or accelerate resistance among vulnerable populations.

## Synonyms

prevention

## Usage notes

- Plural is 'prophylaxes'.

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