An immunity passport is a special piece of paper that says you are safe from a particular sickness, like COVID-19. Doctors give you the paper when they test your blood and find out that your body has made the right kind of soldiers, called antibodies, to fight against the sickness.
Sort of like how your favorite video game has a level select screen, the immunity passport lets you select which places you can go into. If you want to go to crowded places like the playground or a birthday party, you'll need the passport to show to the grown-ups there. If they see that you have the paper, it means you are safe to play with other kids without getting sick or making them sick.
Sometimes, people talk about whether or not the passport is fair. They worry that kids who can't get the passport or who don't have parents that can take them to the doctor might not be able to go to fun places. That's why some people think it's important to make sure everyone can get the passport and that it's not just for rich or lucky kids.
Overall, the immunity passport is like a special key that lets you go to fun and safe places without worrying about getting sick!