1. Unit 4 - Immunology and Public Health

2. Unit 4 – Immunology and Public Health
1. The Immune System
2. Infectious Diseases and immunity
Non-specific defences
Specific cellular defences
Transmission and control
Active Immunisation and Vaccination and the evasion of immune responses

3. By the end of this section you will be able to …..
1. The Immune System b) specific cellular defences
By the end of this section you will be able to …..
describe what is meant by immunological memory
state the benefits of having memory cells.

4. From primary to secondary 

5. Primary response
When a pathogen infects the body, it takes time to raise an immune response and select the correct T and B cells (clonal selection) and produce antibodies.
This is called the primary response, and very often it is too slow to prevent the pathogen causing illness.

6. Secondary response
However, if the person survives, and they come across the SAME pathogen a second time, they will have a much different secondary response!
This is because the body has created MEMORY CELLS
Some of the T and B lymphocytes that were produced by clonal selection after the first exposure survive long term as MEMORY CELLS.
When the SAME foreign antigen is recognised by these memory cells a second time, they very quickly form many clones of both T cells and antibody-producing B cells.
This means that their are more antibodies produced faster and for a longer duration.
This is the secondary response.

11. Can you now …. describe what is meant by immunological memory
state the benefits of having memory cells.