title: The rationale of immunization.
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001428:Bacterial Vaccines; D002648:Child; D002675:Child, Preschool; D003906:Developing Countries; D049673:History, 20th Century; D006801:Humans; D007114:Immunization / Q000266:history; D007115:Immunization Schedule; D007223:Infant; D006113:United Kingdom; D014481:United States; D014611:Vaccination / Q000266:history; D014765:Viral Vaccines
chemical_list: D001428:Bacterial Vaccines; D014765:Viral Vaccines