Preliminary Safety Assessment of a Quadrivalent Subunit Influenza Vaccine in China

This study evaluates the safety of the quadrivalent subunit influenza vaccine in individuals aged 3 years and older in Jiangsu Province, China. The primary objectives are to assess the occurrence of very rare adverse reactions (incidence \

Inclusion Criteria 1. Healthy individuals aged 3 years or above. 2. The participant (and/or their guardian/legal representative) has provided informed consent, voluntarily agreed to participate, signed the Informed Consent Form, and is able to comply with the requirements of this study protocol. Exclusion Criteria 1. Individuals with a known allergy to any component of the vaccine, including eggs, excipients, formaldehyde, or Triton N-101. 2. Individuals suffering from an acute illness, severe chronic disease, an acute exacerbation of a chronic disease, common cold, or fever. 3. Individuals with uncontrolled epilepsy or other progressive neurological disorders, or a history of Guillain-Barré syndrome. 4. Any other condition considered by the investigator as inappropriate for participation in this study.