How are vaccines related to memory cells

Hello!

Although vaccines sound as if they are a medicine made to resist an infection or disease, this is not entirely what they are.
A vaccine is often a dulled version of a disease. This causes your cells to fight the dulled disease/infection. Your memory cells will remember how the vaccine's dulled disease was fought, and it will prepare your body to fight the full disease if you catch it in the future. 

I hope this helps answer your question!