en.wikipedia.org
Vaccine
Preparation for acquired immunity to disease
- A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease.
- The safety and effectiveness of vaccines has been widely studied and verified.
- A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins.
- The agent stimulates the immune system to recognize the agent as a threat, destroy it, and recognize further and destroy any of the microorganisms associated with that agent that it may encounter in the future.