Phase III Clinical Trial of Sabin Strain Inactivated Poliovirus Vaccine (Vero Cell)

Inclusion Criteria: 1. Healthy permanent residents aged 2 months (60\~89 days); 2. Infant's legal guardians agree to sign the informed consent forms voluntarily; 3. Infant's legal guardians are able to comply with the requirements of the clinical trial protocol; 4. Armpit temperature ≤ 37.0 ℃ Exclusion Criteria: 1. preterm birth (gestational age \< 37 weeks); 2. the presence of congenital malformations, developmental disorders, genetic defects, or severe malnutrition; 3. had a history of poliomyelitis; 4. had a personal or family history of allergy, convulsions, epilepsy, encephalopathy, or psychiatric disorders; 5. had known hypersensitivity to any component of the study vaccine or a history of severe allergic reaction (e.g., anaphylaxis) to any previous vaccination; 6. had immunodeficiency or receipt of immunosuppressive therapy; 7. diagnosed coagulation disorders (including factor deficiencies, coagulopathies, platelet abnormalities) or evidence of significant bruising/bleeding diathesis; 8. had known or investigator-suspected concurrent acute or active chronic diseases (including respiratory, cardiovascular, hepatic, renal, or dermatological conditions) or acute infection, or maternal HIV infection; 9. occurrence of fever (axillary temperature ≥ 38.0 °C) within the 3 days preceding enrollment; 10. had acute illness requiring systemic antibiotic or antiviral treatment within the 7 days preceding enrollment; 11. administration of blood products within the 3 months preceding enrollment; 12. had receipt of any live attenuated vaccine within the 14 days preceding enrollment; 13. had receipt of any inactivated or subunit vaccine within the 7 days preceding enrollment; 14. had recent administration of any other experimental product and any other condition deemed by the investigator as potentially interfering with the assessment of trial outcomes.