acellular

adjective

acel·​lu·​lar (ˌ)ā-ˈsel-yə-lər How to pronounce acellular (audio)
1
: containing no cells
acellular vaccines
2
: not divided into cells : consisting of a single complex cell
used especially of protozoa and ciliates

Examples of acellular 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.
Recent data from the CDC shows the vaccinations rates for kindergarteners in the 2024-2025 school year continued to decline, with a dip to 92.1 percent for the diphtheria, tetanus, and acellular pertussis vaccine and to 92.5 percent for the measles, mumps and rubella vaccine and polio shot. Lexi Lonas Cochran, The Hill, 4 Sep. 2025 In seventh grade, students must also get a dose of Tdap (tetanus, diphtheria, acellular pertussis). Ashley J. Dimella, FOXNews.com, 3 Sep. 2025 Rates for the diphtheria, tetanus, and acellular pertussis vaccine otherwise known as the DTaP vaccine have fallen from 94.9% in 2019-2020 to 92.3% in 2023-2024 to 92.1% this past school year. Bruce Y. Lee, Forbes.com, 10 Aug. 2025 At the time, three childhood vaccines contained thimerosal: the diphtheria, tetanus, acellular pertussis (DTaP), hepatitis B and type b (Hib) vaccines. Tara Haelle, Scientific American, 25 June 2025 Today’s whooping cough vaccines contain an acellular pertussis component, which is derived from inactive parts of the bacterium that causes whooping cough, Bordetella pertussis, per CDC. Caroline C. Boyle, USA Today, 20 Apr. 2025 The acellular vaccine is still an effective vaccine. Melissa Dahl, NBC News, 22 Feb. 2025 One is that cases are more commonly occurring in older kids and adults in whom the less reactive acellular pertussis vaccines have replaced older, original whole-cell pertussis vaccines. Judy Stone, Forbes, 16 Oct. 2024

Word History

First Known Use

1857, in the meaning defined at sense 1

Time Traveler
The first known use of acellular was in 1857

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Cite this Entry

“Acellular.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/acellular. Accessed 18 Sep. 2025.

Kids Definition

acellular

adjective
acel·​lu·​lar (ˈ)ā-ˈsel-yə-lər How to pronounce acellular (audio)
: not made up of cells

Medical Definition

acellular

adjective
acel·​lu·​lar (ˈ)ā-ˈsel-yə-lər How to pronounce acellular (audio)
1
: containing no cells
acellular vaccines
2
: not divided into cells : consisting of a single complex cell
used especially of protozoans and ciliates
Last Updated: - Updated example sentences
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