prophylaxis

noun

pro·​phy·​lax·​is ˌprō-fə-ˈlak-səs 

 also  ˌprä-

plural prophylaxes ˌprō-fə-ˈlak-ˌsēz 

 also  ˌprä-

: measures designed to preserve health (as of an individual or of society) and prevent the spread of disease

Did you know?

In Greek, phylax means "guard", so prophylactic measures guard against disease by taking action ahead of time. Thus, for example, before the polio vaccine became available, prophylaxis against polio included avoiding crowds and public swimming pools. These days a well-known kind of prophylactic is used to prevent sexually transmitted diseases; but prophylactic measures only work when people use them.

Examples of prophylaxis in a Sentence

Recent Examples on the Web

When taken regularly, pre-exposure prophylaxis medications like Truvada and Descovy offer significant protection to uninfected people. —Dave Wessner, Forbes, 1 Dec. 2024

The Kind Clinic was started in 2015 to make HIV care and HIV prophylaxis medications more available and affordable. —Nicole Villalpando, Austin American-Statesman, 8 July 2024

The subsequent approval of the HIV-prevention pill — called pre-exposure prophylaxis, or PrEP — in 2012 only hastened the decline. —Benjamin Ryan, NBC News, 12 Nov. 2024

The latter option, called PEP, for post-exposure prophylaxis, has to be started within 72 hours of exposure to be effective. —Keren Landman, Vox, 7 Dec. 2018

Word History

Etymology

borrowed from New Latin, from Greek prophylak-, stem of prophylássein "to keep guard before a place, be on guard, (middle voice) to be on one's guard against, take precautions against" (from pro- pro- entry 1 + phylássein "to keep watch on, guard, preserve," derivative of phylak-, phýlax "guard, guardian, protector") + -sis -sis — more at phylactery

First Known Use

1683, in the meaning defined above

Phrases Containing prophylaxis

• post-exposure prophylaxis
• preexposure prophylaxis

Medical Definition

prophylaxis

noun

pro·​phy·​lax·​is -ˈlak-səs 

plural prophylaxes -ˈlak-ˌsēz 

: measures designed to preserve health and prevent the spread of disease : protective or preventive treatment

prophylaxis against viral diseases

a paste containing fluorine for dental prophylaxis