More measles--why?
D002648:Child; D002675:Child, Preschool; D006801:Humans; D008457:Measles / Q000453:epidemiology* / Q000517:prevention & control; D008458:Measles Vaccine / Q000008:administration & dosage; D012424:Rural Population; D014481:United States; D014505:Urban Population
D008458:Measles Vaccine