Year 9 Science · Unit 1 · Lesson 8

Vaccination and Immunity

Foundation Worksheet

Name

Date

Class

Learning Goals

Use key immunity vocabulary correctly in context (antigen, antibody, B cell, T cell, memory cell)
Match immunity terms to their definitions
Explain how vaccines create protection without causing disease

Warm Up

Fill the gap

Choose the correct word from the word bank to complete each sentence. Two words in the bank are distractors, they will not be used.

antigen antibody B cell T cell memory cell vaccine immunity complement pathogen

Every pathogen has surface molecules called s that the immune system recognises as foreign. When a detects these molecules, it divides and produces large amounts of a specific protein called an , which locks onto the pathogen and marks it for destruction. Helper s activate both B cells and killer T cells, coordinating the adaptive immune response. After the infection is cleared, long-lived s remain in the body and enable a faster, stronger response if the same pathogen is ever encountered again. A works by presenting the immune system with a harmless form of a pathogen or its proteins, triggering this response without causing disease, which is how lasting is achieved safely.

Your Turn

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

Term	Your answer	Definition
Active immunity		A. Antibodies transferred from another source (e.g. breast milk or injection); provides temporary protection without memory cells.
Passive immunity		B. A substance added to a vaccine to boost the immune response.
Herd immunity		C. A vaccine that uses instructions for cells to make a pathogen protein (e.g. Pfizer COVID-19).
Live-attenuated vaccine		D. Immunity produced by the body's own B cells and T cells, with memory cells that provide long-lasting protection.
mRNA vaccine		E. A vaccine that uses a weakened but living form of the pathogen (e.g. MMR).
Adjuvant		F. Indirect protection of unvaccinated individuals because enough people around them are immune to block disease transmission.

Show What You Know

1. Explain how a vaccine causes the immune system to produce memory cells. Use the words antigen, B cell, and memory cell in your answer.

Recall 3 marks

2. A newborn baby receives some protection against infection from its mother's breast milk. Is this active or passive immunity? Explain how this type of immunity differs from the protection given by vaccination.

Recall 2 marks

Wrap Up

In one sentence, explain why vaccines can protect people without making them sick.