Q: Why do I need to get a booster shot for a disease I've already been vaccinated against?
A: A vaccine protects you from a disease by teaching your body to recognize and fight the pathogen that causes the disease. It does this by creating memory T & B-cells. But because the # of memory cells can decrease over time, your body can forget what a certain pathogen looks like, and consequently no longer be ready to fight it. A booster shot is just another vaccine shot that reminds your body how to recognize the pathogen.


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