The Parent of a Young Patient Asks the Nurse Why

The parent of a young patient asks the nurse why the child should receive the measles-mumps-rubella vaccination. What is the nurse's best response?

A) "Your child will develop immunity to these illnesses even without the vaccination, but at a slower rate."
B) "The child can always receive the vaccination later."
C) "Receiving the vaccination will cause your child to develop active acquired immunity, which will protect against the development of these illnesses."
D) "I know the Centers for Disease Control expects everyone to have this vaccination, but you can always refuse."