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What are germs? (for children)

Dr. Jeff Pernica, infectious diseases specialist, McMaster Children’s Hospital

What are germs?

Germs are little tiny animals that nobody can see. If they get into your body, they can make you sick.

Our bodies are made of tiny little living pieces called “cells.” Everyone is made up of these little tiny pieces called “cells.” They’re so small you can’t see them with your regular eyes. You can only see them with a microscope. Now if these tiny, tiny, tiny germs get into our bodies, they can make the cells sick. And if our cells get sick, because they make up our bodies, then we get sick.

Now there’s a part of your body whose job it is to fight germs and stop them from making you sick. The “immune system cells” are the parts of your body that fight germs. Now if they have seen a germ before, then they can fight it well and you don’t get sick. Or if you have gotten a vaccination, so a needle in your arm, that teaches the immune system cells in your body to fight the germs and you don’t get sick.

But if a new germ comes, that your immune system cells don’t know, then sometimes your body has problems fighting the germ and you get sick.