Edexcel iGCSE Biology-3.13B Vaccinations- Study Notes- New Syllabus

Vaccination and Memory Cells

📝 Introduction

Vaccination is the process of introducing a weakened or inactive pathogen (or its antigens) into the body.
Purpose: Stimulate the immune system without causing disease.
Prepares the body for faster and stronger response if the real pathogen attacks later.

🔑 How Vaccination Works

• Exposure to Antigens: Vaccine contains antigens from the pathogen (dead, weakened, or protein fragments). Lymphocytes detect antigens → immune response is triggered.
• Antibody Production: Lymphocytes produce specific antibodies against the pathogen. Pathogen is destroyed, but body remembers it.
• Memory Cell Formation: Some lymphocytes become memory cells. These “remember” the antigen for years or decades.
• Future Exposure to Pathogen: Memory cells respond sooner, faster, and stronger. Rapid production of antibodies → infection is prevented or minimized.

🔑 Key Points

• Vaccination does not cause disease (antigen only, not live pathogen).
• Memory cells allow long-term immunity.
• Booster doses may be needed to reinforce immunity.

📊 Summary Table

⚡ Quick Recap
Vaccination → antigens → lymphocytes → antibodies + memory cells.
Memory cells = rapid future response → faster, stronger, larger quantity of antibodies.
Provides immunity without causing disease.