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

The new guidelines also confirm a maximum daily dose of 200 mg, and recommend reassessing a patient’s need for prophylaxis every three to six months, including regular STI testing. —Annalisa Merelli, STAT, 4 June 2024

While effects against gonorrhea may be limited, and further interventions such as vaccines may be indicated, the prophylaxis has a chance of controlling the spread of chlamydia and syphilis, said Connie Celum, a professor of global health, medicine, and epidemiology at the University of Washington. —Annalisa Merelli, STAT, 4 June 2024

Some antivirals are also approved for post-exposure prophylaxis, meaning that they are given to people who have not yet developed the illness but have had exposure to the virus. —Katia Hetter, CNN, 11 Apr. 2024

People exposed to measles who cannot document immunity against the virus should get post-exposure prophylaxis — a dose of the vaccine to potentially provide protection within 72 hours of initial exposure, or immunoglobulin within six days of exposure. —Kristen Jordan Shamus, Detroit Free Press, 10 Apr. 2024

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

• 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