After getting vaccinated, you develop immunity to that disease, without having to get the disease first. How does a vaccine for a particular disease immunise the body against that disease ?

Explanation

### Step-by-Step Solution:

1. **Understanding Vaccination**: Vaccination is a method of inducing immunity without causing the actual disease. It involves the introduction of a vaccine into the body.

2. **Composition of Vaccines**: Vaccines typically contain killed (inactivated) or attenuated (weakened) forms of the pathogen (virus or bacteria) that causes the disease. These forms are not capable of causing the disease but can still provoke an immune response.

3. **Immune Response Activation**: When the vaccine is administered, the immune system recognizes the components of the vaccine as foreign substances, known as antigens. This triggers an immune response.

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