prophylaxis

noun

pro·​phy·​lax·​is ˌprō-fə-ˈlak-səs How to pronounce prophylaxis (audio)
 also  ˌprä-
plural prophylaxes ˌprō-fə-ˈlak-ˌsēz How to pronounce prophylaxis (audio)
 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 Developing long-acting ways of treating HIV has become a major focus in efforts to manage the virus, including to prevent infection, known as pre-exposure prophylaxis, or PrEP. Robert Hart, Forbes, 21 Feb. 2024 The patient should then be tested, post-exposure prophylaxis should be provided to close contacts and all contacts who are not up to date on their measles vaccinations should be vaccinated. Mary Kekatos, ABC News, 27 Jan. 2024 People who were possibly exposed received post-exposure prophylaxis immune globin, using plasma containing antibodies to immediately protect against measles. Eduardo Cuevas, USA TODAY, 9 Jan. 2024 InMOTION also partners with community health workers to identify people who do not have HIV and are eligible to receive pre-exposure prophylaxis (PrEP), which helps prevent the virus, said Springer. Anika Nayak, STAT, 10 Nov. 2023 This continuum of datapoints highlights the neglected and growing need for prophylaxis of diarrhea in cancer patients. Miami Herald, 25 Jan. 2024 Intravenous magnesium used as a prophylaxis turned out to be the answer. Rachel Nuwer, Scientific American, 5 Jan. 2024 Millions more avoided infecting others or were protected from being infected with HIV thanks to PrEP (pre-exposure prophylaxis). Lori Youmshajekian, Scientific American, 22 Nov. 2023 The whole class will ride these cardiovascular disease benefits and future data will reveal benefits for liver disease, some cancers, and as prophylaxis for pre-diabetics. Bob Kocher, Fortune, 14 Nov. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'prophylaxis.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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

Time Traveler
The first known use of prophylaxis was in 1683

Dictionary Entries Near prophylaxis

Cite this Entry

“Prophylaxis.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/prophylaxis. Accessed 18 Mar. 2024.

Medical Definition

prophylaxis

noun
pro·​phy·​lax·​is -ˈlak-səs How to pronounce prophylaxis (audio)
plural prophylaxes -ˈlak-ˌsēz How to pronounce prophylaxis (audio)
: 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

More from Merriam-Webster on prophylaxis

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