Explain how vaccination protects both an individual and the wider population from a communicable disease.

Eduqas GCSE Biology — 3.1 Health and disease · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

A vaccine contains weakened or dead pathogens or antigens from the pathogen. The immune system recognises these antigens and produces antibodies and other white blood cells, creating memory cells. If the vaccinated person is later exposed to the real pathogen, the memory cells trigger a rapid and stronger antibody response, preventing illness. When a large proportion of the population is vaccinated, the pathogen cannot spread easily – this is herd immunity – which protects even those who are not vaccinated.

Examiner tips

  • Use the word ‘antigens’ and ‘memory cells’ – these are key terms.
  • Show the sequence: vaccine → immune response → memory cells → protection.
  • Mention herd immunity explicitly to cover the population aspect.
  • Keep the answer concise – 4 marks only.

Mark scheme (4 marks)

  1. Vaccine contains weakened/dead pathogens or antigens from the pathogen
  2. The immune system produces antibodies / white blood cells respond, creating memory cells
  3. If the individual is exposed to the real pathogen, memory cells allow a faster/greater antibody response so the person does not become ill
  4. When a large proportion of the population is vaccinated, the pathogen cannot spread easily (herd immunity), protecting unvaccinated individuals

Key terms in this question

vaccination · communicable disease

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