Lot-to-lot Consistency Study of Three Commercial Batches of Enterovirus 71 Vaccine

Inclusion Criteria: * Age Requirement: Children aged 6 to 35 months at the time of enrollment. * Provision of legal Identification: Volunteers and their legal guardians or appointed representatives must provide valid legal identification documents. * Informed Consent: Legal guardians or appointed representatives of volunteers must have the capacity to understand the informed consent document and the research process, voluntarily participate, sign the informed consent form, and be able to comply with the study's requirements and complete relevant visits on time. * Temperature Requirement: Axillary body temperature prior to vaccination is less than 37.3°C. Exclusion Criteria: \[First Dose Exclusion Criterions\] Subjects meeting any of the following exclusion criteria will not be eligible for enrollment * Allergic History: Subjects have a previous history of allergies to any component of the vaccine (e.g., aluminum hydroxide, glycine), or previous or suspected allergy to any vaccine or other serious adverse reaction (e.g., anaphylactic shock, laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local anaphylactic necrosis reaction, dyspnea, angioedema, systemic rash and/or urticaria, etc.). * Vaccination History: Subjects received any inactivated vaccine or subunit vaccine within 7 days prior to the first dose of the investigational vaccine or any live attenuated vaccine within 14 days prior to the first dose of the investigational vaccine. * Neurological and Men…