Question

since many childhood diseases such as mumps and measles are rare now within the united states, why is it still important for children to be immunized against them?

Answer 1

We want to have as much herd immunity as possible. Although rare, they still happen. If an unvaccinated child is exposed to MMR, they will develop symptoms and spread to other unvaccinated children. Immunocompromised children that may not be able to receive the vaccine would be at a disadvantage and also develop the disease.