Biology A-Level
herd immunity
What herd immunity means in Biology A-Level, as defined for AQA.
Definition of herd immunity
Check what you remember
Read the wording for your board, then hide it and explain herd immunity in your own words. Rough notes are fine. This is a self-check, with no mark or grade.
Reference: AQA
If a large enough proportion of people are immune, an infected person is unlikely to meet a susceptible one, so transmission is interrupted and the pathogen cannot circulate.
Topics that use herd immunity
- Cell recognition and the immune system (AQA A-Level)
Related terms
- active immunity
- agglutination
- animal use in production and testing
- antibody
- antigen
- antigen-antibody complex
- antigen-presenting cell
- antigens in vaccines
Using herd immunity in the exam
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