To evaluate the safety and immunogenicity of quadrivalent influenza virus split vaccine in healthy population aged 3-8 years following different immunization procedures, and the participants randomized to receive two injections of 0.5 mL quadrivalent influenza vaccine at day 0 and 28.
To evaluate the safety and immunogenicity of quadrivalent influenza virus split vaccine in healthy population aged 3-8 years following different immunization procedures.