Immunization of preschool children with oral poliovirus vaccine (Sabin).
D002648:Child; D002675:Child, Preschool; D006801:Humans; D007114:Immunization; D011051:Poliomyelitis / Q000276:immunology*; D011055:Poliovirus Vaccine, Oral; D014611:Vaccination
D011055:Poliovirus Vaccine, Oral
POLIOMYELITIS/immunology