Immune system retains the memory of which response in vaccination process.

Options

A. Passive immunization response
B. Primary immune response
C. Secondary immune response
D. All of the above

Answer

To answer the question about which response the immune system retains memory of during the vaccination process, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Immune Responses**:
- The immune system has two main types of responses: primary immune response and secondary immune response.
- The primary immune response occurs when the body is exposed to a pathogen for the first time.

2. **Role of Memory Cells**:
- During the primary immune response, the body produces memory cells that "remember" the specific pathogen.
- These memory cells can persist in the body for several years, typically around 4 to 5 years.

3. **Vaccination Process**:
- Vaccination involves introducing a weakened or inactivated form of a pathogen into the body.
- This does not cause disease but stimulates the immune system to produce a primary immune response.

4. **Memory Retention**:
- The memory cells generated during the primary immune response are crucial because they allow the immune system to respond more rapidly and effectively if the same pathogen is encountered again in the future.
- This rapid response upon subsequent exposure is known as the secondary immune response.

5. **Analyzing the Options**:
- The question provides four options:
1. Passive immunization response
2. Primary immune response
3. Secondary immune response
4. All of the above
- Since the immune system retains memory specifically from the primary immune response generated during vaccination, the correct answer is the primary immune response.

### Conclusion:
The immune system retains the memory of the **primary immune response** during the vaccination process.