This study of quadrivalent influenza vaccine will be open-label design in phase Ⅰ and randomized, double-blind, active controlled design in phase III.The quadrivalent influenza vaccine was manufactured by Sinovac Biotech Co., Ltd.~The purpose of this study is to evaluate the safety and immunogenicity of quadrivalent influenza vaccine(0.25ml and 0.5ml) manufactured by Sinovac Biotech Co., Ltd in healthy infants aged from 6 to 35 months. A total of 3330 subjects including 30 subjects in phase Ⅰ and 3300 subjects in phase III will be enrolled. The subjects in phase Ⅰ will receive 2 doses of quadrivalent influenza vaccine(0.5ml) on the immunization schedule of day 0,28.The subjects in phase III will be randomly assigned to 4 groups in a 2:2:1:1 ratio and subjects will receive two doses of quadrivalent influenza vaccine(0.25ml or 0.5ml) or trivalent influenza vaccine(BV or BY), respectively,on the immunization schedule of day 0,28 in each group.
The study of quadrivalent influenza vaccine manufactured by Sinovac Biotech Co., Ltd will conduct in two phases,the phaseⅠclinical trial of the study will be open-label design,and the phase III clinical trial of the study will be randomized, double-blind, active controlled design.the purpose of this study is to evaluate the safety and immunogenicity of quadrivalent influenza vaccine in healthy subjects aged 6 to 35 months.