How do vaccinations work to keep patients healthy?

Vaccines expose the immune system to a harmless or weakened form of a pathogen, or to a piece of it. This helps the body learn to recognize it and prepare defenses, such as antibodies, so it can respond more effectively later. Vaccinations do not remove every pathogen from the body, add white blood cells, or strengthen the skin barrier; the correct choice is “They introduce a weakened form of a disease so the body can learn how to fight it off.”

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