Immunogenicity of Japanese Encephalitis Vaccine Co-administered with Measles-Mumps-Rubella Vaccine (MMR)

Inclusion Criteria:

• Participants aged 8 months to <12 months at the time of enrollment

• Participants are able to provide valid identification documents of themselves and/ortheir legal guardian (entrusted person).

• Legal guardian of the participants can understand requirements and processes of thestudy, voluntarily agree to participate in the clinical trial, provide informedconsent, accept all scheduled visits.

Exclusion Criteria:

• Axillary temperature >37.0 ℃ at the time of enrollment.

• Participating in another clinical trial or planning to participate in anotherclinical trial during the course of this trial.

• Previous receipt of the Japanese encephalitis vaccine or the measles-mumps-rubellavaccine (or a vaccine containing any of these components), or plan to receive othervaccines of the same type or composition during the trial period.

• History of measles, mumps, rubella, or Japanese encephalitis infection (confirmed byclinical, serological, or microbiological methods).

• Received blood or blood products within 3 months before enrollment.

• History of allergies to any component of the experimental vaccine, or severeallergies to other vaccine or drugs administered in the past, such as anaphylacticshock, laryngeal edema, henoch-schonlein purpura, thrombocytopenic purpura, arthurreaction, dyspnea, angioneuroedema, systemic rash and/or urticaria.

• History of attenuated live vaccine administration within 14 days prior tovaccination, or history of other non live vaccine administration within 7 days priorto vaccination.

• Acute febrile diseases (axillary body temperature ≥ 38.5 ℃) or in acute stage ofchronic diseases, or taking antipyretics, analgesics, and anti-allergic agentswithin 3 days before vaccination.

• Primary or acquired immunodeficiency, such as human immunodeficiency virus infection (participants themselves or their mothers are infected with human immunodeficiencyvirus), systemic lupus erythematosus, guillain-barre syndrome, or other autoimmunediseases.

• Primary or acquired immune dysfunction (history of thyroid, pancreatic, liver, andspleen resection)

• Receipt of immunosuppressive therapy within 3 months prior to enrollment, such ascytotoxic therapy, steroid therapy (defined as continuous oral or intravenousinfusion for more than 14 days, with a glucocorticoid dose of ≥0.5 mg/kg/day,unrestricted for inhaled and local steroids), or long-term other immunomodulatorydrugs.

• Serious illness (acute or chronic), known or suspected, such as complicateddiabetes, infectious, purulent, and allergic skin diseases, Down's syndrome, sicklecell anemia, cardiovascular and cerebrovascular diseases, liver and kidney diseases,respiratory diseases, malignant tumors, etc.

• Contraindications to intramuscular injection, such as diagnosed withthrombocytopenia, any coagulation disorders, or receiving anticoagulant treatment.

• History of convulsions, epilepsy, encephalopathy, mental illness or otherneurological disorders, or a family history of mental illness.

• Plans to move out of the local area before the end of the experiment or leave thelocal area for a long time during the scheduled trial visit period.

• Any conditions that may interfere with the evaluation of the experimental purpose,as deemed by the researcher.