vaccinia

noun

vac·​cin·​ia vak-ˈsi-nē-ə How to pronounce vaccinia (audio)
1
or vaccinia virus : a poxvirus (species Vaccinia virus of the genus Orthopoxvirus) that differs from but is closely related to the viruses causing smallpox and cowpox and that includes a strain used in making vaccines against smallpox
2
: a reaction to smallpox vaccine prepared from live vaccinia virus that may involve a rash, fever, headache, and body pain
vaccinial
vak-ˈsi-nē-əl How to pronounce vaccinia (audio)
adjective

Examples of vaccinia in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
If someone gets severely ill, the US CDC has said that two other treatments—a monoclonal antibody called vaccinia immune globulin and an antiviral called cidofovir—can be used. — David Cox, WIRED, 27 July 2022 Regulators in Nigeria have recently approved the Bavarian Nordic vaccine, and the DRC’s Ministry of Health has endorsed use of both weakened vaccinia products. — Byjon Cohen, science.org, 19 Apr. 2024

Word History

Etymology

earlier, "cowpox," from New Latin vaccina (in variolae vaccinae "cowpox") + -ia -ia entry 1 — more at vaccine

First Known Use

1800, in the meaning defined at sense 1

Time Traveler
The first known use of vaccinia was in 1800

Rhymes for vaccinia

See All Rhymes for vaccinia

Browse Nearby Words

vaccinia
See all Nearby Words

Cite this Entry

“Vaccinia.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/vaccinia. Accessed 25 Mar. 2025.

Copy Citation

Share

Medical Definition

vaccinia

noun
vac·​cin·​ia vak-ˈsin-ē-ə How to pronounce vaccinia (audio)
1
a
: cowpox
b
: a reaction to smallpox vaccine prepared from live vaccinia virus that may involve a rash, fever, headache, and body pain
2
or vaccinia virus : a poxvirus of the genus Orthopoxvirus (species Vaccinia virus) that differs from but is closely related to the viruses causing smallpox and cowpox and that includes a strain of uncertain natural origin used in making vaccines against smallpox
vaccinial
-ē-əl How to pronounce vaccinia (audio)
adjective

More from Merriam-Webster on vaccinia

Britannica.com: Encyclopedia article about vaccinia

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

The Difference Between 'i.e.' and 'e.g.'

Why is '-ed' sometimes pronounced at the end of a word?

Words You Always Have to Look Up

Democracy or Republic: What's the difference?
See More

Popular in Wordplay

See More

Top 10 Sophisticated Insults

Flower Etymologies For Your Spring Garden

More Words with Remarkable Origins

Terroir, Oenophile, & Magnum: Ten Words About Wine

8 Words for Lesser-Known Musical Instruments
See More

Popular Features

See More

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

Top 10 Sophisticated Insults

Flower Etymologies For Your Spring Garden
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Word Game Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
dog-in-disguise
Rhyme Disguise Quiz Pair up words that look different but sound alike.
See All