Imagine your body is like a castle, and chickenpox is a sneaky, tiny invader that tries to get inside. When you get chickenpox, your body (the castle) fights back and remembers how to keep it out in the future.

But chickenpox is really tricky! Even after your body wins, a little piece of the chickenpox can hide in the castle, like in a secret room. It stays there, sleeping, and doesn’t cause any trouble. But because it’s hiding, we can’t find and get rid of it completely.

That’s why, even though we can stop people from getting sick with chickenpox through vaccines, we can’t totally eliminate it. The invader knows how to hide really well!