title: Spot the difference.
mesh_terms: D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000706:statistics & numerical data*; D006801:Humans; D032521:Immunity, Herd / Q000276:immunology; D007223:Infant; D038622:Internationality; D008457:Measles / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control*; D008458:Measles Vaccine / Q000008:administration & dosage / Q000276:immunology; D011639:Public Opinion; D011998:Recreation; D018570:Risk Assessment; D013219:State Government; D014481:United States / Q000453:epidemiology; D014611:Vaccination / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*
chemical_list: D008458:Measles Vaccine