Vaccination
Revise Vaccination for GCSE Biology with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. A vaccine introduces a dead or inactive form of a pathogen so white blood cells produce antibodies and memory cells for a rapid future response.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Vaccination involves introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate the white blood cells to produce antibodies.
Because the pathogen is dead or inactive, it cannot cause the disease. But the immune system responds as if it were a real infection, producing antibodies specific to that pathogen and, crucially, memory cells.
If the same live pathogen later enters the body, those memory cells allow antibodies to be produced far more rapidly and in much greater quantity. The pathogen is destroyed before it can multiply enough to cause symptoms, so the person is immune.
Revision notes
How a vaccine works
A small quantity of dead or inactive pathogen is introduced into the body.
White blood cells respond by producing antibodies specific to that pathogen. Because the pathogen is inactive, no disease is caused.
The secondary response
Memory cells remain in the body after vaccination.
If the live pathogen enters later, antibodies are produced much more quickly and in much greater quantity, destroying the pathogen before symptoms develop.
Herd immunity
If a large proportion of the population is immune, the pathogen has few hosts to infect, so it spreads far less readily.
This protects even those who are not vaccinated, which is why vaccination programmes aim for high uptake.
Key points
- A vaccine contains dead or inactive pathogen.
- It stimulates white blood cells to produce antibodies.
- The inactive pathogen cannot cause the disease.
- Memory cells remain after vaccination.
- A second exposure produces antibodies faster and in greater quantity.
- High vaccination rates protect the wider population.
Worked examples
Example 1
Explain how vaccination makes a person immune to a disease. [4 marks]
Model answer
A small quantity of dead or inactive pathogen is introduced into the body (1 mark). This stimulates the white blood cells to produce antibodies specific to that pathogen (1 mark). Memory cells remain in the body afterwards (1 mark), so if the live pathogen enters later, antibodies are produced much more rapidly and in greater quantity, destroying it before symptoms develop (1 mark).
Example 2
Explain why a vaccine does not give a person the disease. [2 marks]
Model answer
The pathogen in the vaccine is dead or inactive (1 mark), so it cannot reproduce inside the body or produce toxins, and therefore cannot cause the disease (1 mark).
Example 3
Explain how vaccinating a large proportion of a population protects those who are not vaccinated. [2 marks]
Model answer
If most people are immune, the pathogen has very few hosts it can infect (1 mark), so it spreads far less readily and unvaccinated people are less likely to encounter it (1 mark).
Common mistakes
Saying a vaccine contains antibodies.
It contains dead or inactive pathogen. The body then makes its own antibodies.
Forgetting memory cells.
They are what make the second response fast, and usually carry a mark.
Saying the vaccine kills the pathogen.
The vaccine stimulates the immune system; the antibodies produced deal with any later infection.
Not describing the second response.
The full answer needs both the first exposure and what happens on re-exposure.
Exam tips
- Structure your answer as: inactive pathogen, antibodies, memory cells, faster second response.
- Say specific antibodies to show you understand they target one pathogen.
- Mention memory cells explicitly.
- Use herd immunity reasoning when asked about population-level protection.
Key terms
- Vaccine
- A preparation of dead or inactive pathogen used to produce immunity.
- Antibody
- A protein produced by white blood cells targeting a specific pathogen.
- Memory cell
- A white blood cell that remains after infection, allowing a rapid second response.
- Immune
- Able to resist a disease because antibodies can be produced rapidly.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.