Based on which property of immune system, mainly, the principle of vaccination was developed ?

Options

A. ability to distinguish self and nonself
B. diversity
C. memory
D. specificity

Answer

**Step-by-Step Solution:**

1. **Understanding Vaccination**: Vaccination is a method used to provide immunity against specific diseases. It involves introducing a harmless form of a pathogen (like a virus or bacteria) into the body to stimulate the immune system.

2. **Acquired Immunity**: Vaccination is a type of acquired immunity, which means it is not present at birth but develops over time as the body is exposed to pathogens or vaccines.

3. **Role of Memory Cells**: The key aspect of vaccination is the creation of memory cells. When a vaccine is administered, it prompts the immune system to produce antibodies and memory cells that "remember" the specific pathogen.

4. **Response to Future Infections**: If the body encounters the actual pathogen in the future, these memory cells quickly recognize it and mount a strong immune response, effectively neutralizing the threat before it can cause illness.

5. **Identifying the Correct Property**: Among the options provided:
- **Option 1**: Ability to distinguish self and non-self - This is important for the immune system but not the main principle of vaccination.
- **Option 2**: Diversity - While the immune system has diverse responses, this is not the principle behind vaccination.
- **Option 3**: Memory - This is the correct answer, as vaccination relies on the immune system's ability to remember past infections.
- **Option 4**: Specificity - This is also important, but it is not the main principle of vaccination.

6. **Conclusion**: The principle of vaccination is mainly based on the property of memory within the immune system, allowing for a quicker and more effective response to previously encountered pathogens.

**Final Answer**: The principle of vaccination was developed based on the property of memory in the immune system (Option 3).

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