Non-Specific Vs Specific Immunity¶
The immune system makes more sense when it is divided into layers. Some defences are immediate and general. Others are slower at first, but targeted and capable of memory.
Quick Comparison¶
| Feature | Non-specific immunity | Specific immunity |
|---|---|---|
| Response to one pathogen only? | No | Yes |
| Speed on first exposure | Fast | Slower |
| Memory after infection | No | Yes |
| Main examples | Skin, inflammation, clotting, phagocytes | B cells, T cells, antibodies, memory cells |
Non-Specific Defences¶
- These act against a broad range of pathogens.
- They include physical barriers such as skin and mucous membranes.
- They also include processes such as clotting, inflammation and phagocytosis.
- Their strength is speed and breadth, but they do not become more precise after exposure.
Specific Immunity¶
- Specific immunity depends on lymphocytes that recognise particular antigens.
- B cells can form plasma cells that secrete antibodies.
- T helper cells coordinate the response, while T killer cells attack infected cells.
- Memory cells remain after infection or vaccination, which is why the secondary response is faster and stronger.
Why Vaccination Works¶
- Vaccination uses the memory feature of specific immunity.
- The body meets antigen in a controlled way, forms memory cells, and can then respond much more effectively on later exposure.
Common Confusions¶
- Phagocytes are part of the non-specific response even though they are cells and not just barriers.
- Antibodies belong to the specific response because they are produced in response to a particular antigen.
- A stronger secondary response does not mean the pathogen has changed; it means the immune system has changed.