acellular

adjective

acel·​lu·​lar (ˌ)ā-ˈsel-yə-lər 

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

The country saw similar declines for vaccines that protect against polio, hepatitis B, and diphtheria, tetanus and acellular pertussis. — Jackie Flynn Mogensen, Scientific American, 24 Aug. 2026

Adolescents should then receive a Tdap or tetanus, diphtheria and acellular pertussis booster at age 11 or 12. — Faye Chiu, CNN Money, 23 June 2026

The vaccines recommended under the new guidelines include diphtheria, tetanus, acellular pertussis (whooping cough), Haemophilus influenzae type b (Hib), Pneumococcal conjugate, polio, measles, mumps, rubella, and human papillomavirus (HPV), as well as varicella (chickenpox). — Caitlin Yilek, CBS News, 5 Jan. 2026

These early vaccines included diphtheria, tetanus, and acellular pertussis (DTaP); Haemophilus influenzae type b (Hib); pneumococcal conjugate vaccine (PCV); and the inactivated poliovirus vaccines (IPV). — Dr. Crystal Richards, ABC News, 2 Jan. 2026

Word History

Etymology

a- entry 2 + cellular entry 1

First Known Use

1857, in the meaning defined at sense 1

Rhymes for acellular

• subcellular
• cellular
• extracellular
• intercellular
• intracellular
• multicellular
• unicellular
• hepatocellular

Kids Definition

acellular

adjective

acel·​lu·​lar (ˈ)ā-ˈsel-yə-lər 

: not made up of cells

Medical Definition

acellular

adjective

acel·​lu·​lar (ˈ)ā-ˈsel-yə-lər 

1

: containing no cells

acellular vaccines

2

: not divided into cells : consisting of a single complex cell

—used especially of protozoans and ciliates