God designed our bodies with a super-smart system for staying healthy. It’s called the immune system. Its big job is to kick out trespassers called germs.

Another word for “germ” is “antigen.” An antigen is an unwelcome invader in the body. Antigens wake up the body’s immune system. It gets ready to declare war on the intruders!

Bacteria and viruses are two different kinds of antigens. When an antigen enters the body, it gets nice and comfortable. It snacks on nutrients, zaps energy, and causes aches and pains. The body needs help getting rid of it.

That’s when the immune system goes into defense! It makes antibodies. These little guys look like the letter “Y.” They hang out in blood. Their job is to destroy antigens in the body. The result is a battle that plays out like one big game of tag. Antibodies tag infected cells and get rid of them. Then the antigen can’t spread.

The immune system coordinates its strong army of antibodies. Each time a new virus enters the blood, the immune system creates new antibodies. The antibodies get rid of the new antigens. If the same antigen ever comes back, the body will remember it. Often, it can fight it off faster and stronger than before.

A vaccine is a substance that helps develop immunity to an antigen. It doesn’t make a body sick with the antigen, even though it has a tiny bit of the germ in it. But it does cause the body to create antibodies against the germ—even without infection happening!

Scientists are working to create a vaccine for the coronavirus. They use their knowledge of the immune system God created. They help boost that immunity to protect people from harmful diseases that antigen infections cause.