Phase III Clinical Trial of Quadrivalent Influenza Virus Split Vaccine

Inclusion Criteria:

• Age Requirement: volunteers aged 3 years and above at the time of enrollment.

• Provision of Legal Identification: Volunteers and their legal guardians or appointedrepresentatives must provide valid legal identification documents.

• Informed Consent: Volutters, legal guardians, or appointed representatives ofvolunteers must have the capacity to understand the informed consent document andthe research process, voluntarily participate, sign the informed consent form, andbe able to comply with the requirements in the study as well as complete relevantvisits on time.

• Requirements for contraception: agree to take contraception actions in 6 months.

• Temperature Requirement: Axillary body temperature is less than 37.3°C.

• Previous Vaccination Requirements: (a) Received at least 1 dose of influenza vaccinewithin 1 year before screening in children aged 3-8 years; (b) Never received anyinfluenza vaccine 1 year before screening in children aged over 3 years.

Exclusion Criteria:

Subjects meeting any of the following exclusion criteria will be not eligible for enrollment.

• Subjects with a history of severe allergy to egg or egg protein, such as those whohave had symptoms such as angioedema, dyspnea, chest distress, or repeated vomitingdue to eating eggs, and even those who have used epinephrine or other emergencymedical treatment, especially those who have symptoms immediately or within a shortperiod (minutes to hours).

• Subjects with influenza illness (clinically, serologically, or microbiologicallyconfirmed) within 6 months before screening and enrollment.

• Have received an influenza vaccine within 1 year before enrollment or scheduled toreceive another influenza vaccine during the study period.

• Allergic to any component contained in the investigational vaccine, or previoushistory of severe allergic to any vaccine or drug, such as anaphylactic shock,laryngeal edema, anaphylactic purpura, thrombocytopenic purpura, local allergicnecrosis reaction, dyspnea, angioedema, systemic rash and/or urticaria, etc.

• History of taking administration of a non-SARS-CoV-2 inactivated vaccine or subunitvaccine within 7 days before enrollment, or any live attenuated vaccine orSARS-CoV-2 vaccine within 14 days before enrollment, or subjects have scheduled toreceive another vaccine within 1 month after receipt of the investigational vaccine

• Subjects with convulsion, epilepsy, encephalopathy (such as moderate to severehypoxic-ischemic encephalopathy, intracranial hemorrhage, cerebral palsy,intracranial tumor, cerebral infarction, stroke, intracranial infection, etc.),psychiatric history or family history

• Have been diagnosed with a serious medical condition or congenital malformation thatmay interfere with the conduct or completion of the study (including but not limitedto suffering from respiratory diseases such as asthma or during episodes of chronicbronchitis, Down syndrome, thalassemia, heart disease, severe cardiac arrhythmias,kidney disease, diabetes (diabetics with poor glycemic control or severecomplications), autoimmune diseases, genetic allergies, Guillain-Barre syndrome,Crohn disease, malignancies, severe infectious/allergic skin diseases, etc.)

• Adults aged 18 years or older with medically uncontrolled abnormal blood pressure (systolic blood pressure ≥140mmHg and/or diastolic blood pressure ≥90mmHg orsystolic blood pressure ≤ 90mmHg and/or diastolic blood pressure ≤ 60 mmHg)

• Subjects with acute illness or in the acute phase of a chronic illness within 3 daysbefore vaccination

• Subjects with fever (axillary temperature ≥37.3 ° C) within 3 days beforevaccination or use of antipyretic, analgesic, or antiallergic medications

• Subjects with a hereditary bleeding tendency or coagulopathy, or a history ofbleeding disorders

• Have received a blood transfusion or use of blood products within 3 months beforeenrollment, or planned to do so within 1 month after full immunization

• History of surgical removal of the spleen or other vital organs for any reason

• Use of any investigational or unregistered product (drug, vaccine, biologicalproduct, or device) other than a study vaccine within 3 months before enrollment orplanned for use during the study

• Have treatment with immunosuppressive agents within 6 months before enrollment, suchas long-term systemic glucocorticoid therapy (e.g., prednisone or a similar drug formore than 2 consecutive weeks within 6 months), but topical use (e.g., ointments,eye drops, inhalers, or nasal sprays) was allowed. Topical use should not exceed therecommended dose on the label or have any signs of systemic exposure

• Have been diagnosed with an infectious disease that may interfere with the conductor completion of the study, such as active tuberculosis, hepatitis B, hepatitis C,human immunodeficiency virus (HIV) infection, etc

• Being lactating, pregnant (including a positive urine pregnancy test), or planningto become pregnant within 6 months of vaccination

• Subjects plan to move out of the local area before the end of the study or leave thelocal area for an extended period during the scheduled study visit

• Subjects with abnormal vital signs with clinical significance

• Investigators' Discretion: The final exclusion criterion is the discretion ofinvestigators to determine whether a subject is suitable for participation in thestudy.