Years ago, it wasn’t uncommon for a grandma who had already had chicken pox to step in and take care of kids who had the disease. Since she had already had the disease once, she was less likely to catch it again.
Developing immunity
Why? When a disease gets into your body, your immune system jumps into action to fight it off. It can take time for your immune system to figure out just how to combat the disease, so you might still get sick and feel pretty bad for a while.
When your immune system succeeds in fighting off the disease, it has learned something. If it meets the same disease again, it will spring into action faster and more effectively, and it will usually be able to fight off that disease before you even start to feel bad.
That’s why those grandmothers could step in and care for kids with chicken pox. They’ve had the disease before, so they will usually be immune to it.
Vaccines let your immune system learn
The problem is, some diseases are too dangerous to take chances with. Whooping cough (pertussis) killed about 1% of people who caught it before vaccines — 8,000 people every year in the United States.
That’s a deadly disease. 1 in every 100 people who caught whooping cough would die from the disease before their immune system could get its defense together.
A vaccine introduces weak or dead versions of the disease into your body. They’re not strong enough to give you the disease, though you might feel a little worse than normal. They let your immune system practice fighting against that disease safely. If you meet that disease again, you’re less likely to catch it — just as you would be if you had survived the disease.
Do vaccines work? There are now fewer than 20 deaths a year from pertussis in the United States — compared with 8,000 before vaccines.

Vaccines definitely work.
Vaccines are not magic
You are less likely to catch a disease if you’ve been vaccinated against it. This is why we no longer lose half our children to “childhood diseases” like pertussis, measles, and mumps. Vaccines don’t give you 100% immunity against a disease for the rest of your life. It is possible for someone who has been vaccinated to catch a disease from someone who has that disease.
If most people are vaccinated, though, very few people will ever catch those deadly diseases. Most people in the community will never even be exposed to diseases like whooping cough. Your choice to vaccinate your child helps keep your whole community safe.
If you choose not to vaccinate your child, your child might still be okay. If most people have vaccinations, few people will catch the disease. Your child might never be exposed to whooping cough. That’s called the “herd effect.” The vaccinated herd keeps one unvaccinated child safe.
If there are many unvaccinated children, however, the whole community is less safe. Deadly childhood diseases can come back and threaten all our children.
This is why Northwest Arkansas Pediatrics does not treat children who are not vaccinated. Babies too young for vaccinations can be exposed to dangerous diseases if they share a waiting room with an infected child.This is why schools try to make sure all the children in their care have been vaccinated.
If you’re not sure about vaccinations, talk with your pediatrician.