pre-exposure

adjective

pre-ex·​po·​sure ˌprē-ik-ˈspō-zhər 

variants or less commonly preexposure

: occurring, administered, used, or being in the period preceding exposure (as to a stimulus or a pathogen)

pre-exposure rabies vaccination

Canon has also added a red-eye reduction pre-exposure light …

—Herbert Keppler

see also pre-exposure prophylaxis

pre-exposure noun

Rats differ from monkeys and chicks in that simultaneous pre-exposure to two stimuli does facilitate their subsequent discrimination …

—R. A. Hinde

Examples of pre-exposure in a Sentence

Recent Examples on the Web

The number of people who received pre-exposure prophylaxis (PrEP) medication, used to prevent those at risk from contracting HIV, declined by a drastic 38 percent between 2024 and 2025, per initial data from 62 countries — which means more than a million fewer people took the drug. — Rael Ombuor, Washington Post, 13 June 2026

Lewin wrote to Rubio that the number of pregnant and breastfeeding mothers who began pre-exposure prophylaxis through PEPFAR more than doubled. — Shannon K. Kingston, ABC News, 17 Apr. 2026

The event was sponsored by MISTR, a telemedicine platform that provides online access to pre-exposure prophylaxis (PrEP) and long-term HIV care. — Kevin Dolak, HollywoodReporter, 18 Mar. 2026

Study data showed a single set of injections every six months can offer virtually complete protection against infection, a form of prevention known as pre-exposure prophylaxis, or PrEP. — Ed Silverman, STAT, 5 Mar. 2026

Word History

First Known Use

1906, in the meaning defined above

Rhymes for pre-exposure

• nondisclosure
• postexposure
• closure
• crozier
• mosher
• osier
• composure
• cynosure
• disclosure
• enclosure
• exposure
• foreclosure

Medical Definition

pre-exposure

adjective

pre-ex·​po·​sure -ik-ˈspō-zhər 

variants preexposure

: of, relating to, occurring in, or being the period preceding exposure (as to a stimulus or a pathogen)

pre-exposure immunization