If enough kids are not vaccinated, a disease can easily spread within their daycare, classroom, or community.
If your child is medically able to get vaccinations, you can protect those that cannot: newborn babies, kids going through chemotherapy, and more.
A person who has been vaccinated is less likely to get a disease and spread it to others. This is called community immunity. Depending on the disease and how easily it can spread, vaccination rates may need to be as high as 80 to 95 percent for community immunity to take place.
Sources:
CDC: What Would Happen If We Stopped Vaccinations?
CDC: Who Should NOT Get Vaccinated?
The College of Physicians of Philadelphia: History of Vaccines
Children’s Hospital of Philadelphia: Vaccines and the Immune System