# Explain how vaccination protects a person from becoming seriously ill when they are later infected by a pathogen.

> WJEC GCSE Biology (Wales) — 2.8 Disease, defence and treatment · Explain · 4 marks

## Mark scheme (4 marks)

1. The vaccine contains antigens (from the pathogen) / weakened or dead pathogens that carry antigens
2. White blood cells (lymphocytes) produce antibodies in response to the antigens
3. Memory cells are produced / remain in the body after the initial immune response
4. On re-exposure to the pathogen, memory cells allow a faster / larger antibody response so the pathogen is destroyed before the person becomes seriously ill

## Key terms

- [vaccination](https://www.gradenine.co.uk/glossary/vaccination)

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-vaccination-protects-a-person-fed6faae) · Published by Druglandscape Ltd.