Final answer:
A vaccine is a biological preparation that stimulates the immune system to produce immunity against a specific disease.
Step-by-step explanation:
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. It typically contains a weakened or inactivated virus or bacteria, or some of its components, which stimulate the immune system to produce a response similar to that produced by the natural infection, without causing the disease itself.
For example, the flu vaccine contains components of the influenza virus that help the immune system recognize and fight the virus if a person is exposed to it in the future. Vaccines are an important tool in preventing the spread of diseases and protecting individuals and communities.
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