title: Control of poliomyelitis in Bulgaria: experience of two decades.
mesh_terms: D000367:Age Factors; D000917:Antibody Formation; D002031:Bulgaria; D002648:Child; D002675:Child, Preschool; D004769:Enterovirus Infections / Q000453:epidemiology / Q000276:immunology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control*; D011054:Poliovirus Vaccine, Inactivated / Q000276:immunology / Q000627:therapeutic use; D012621:Seasons; D012737:Sex Factors; D014777:Virus Diseases / Q000453:epidemiology
chemical_list: D011054:Poliovirus Vaccine, Inactivated