This study is a phase I& III clinical trial. Phase I is open-labelled, and phase III is randomized, double-blind, active-controlled. The purpose of this study is to evaluate the safety and immunogenicity of the quadrivalent influenza vaccine (QIV) (experimental vaccine) manufactured by Sinovac Biotech Co., Ltd in subjects aged over 3 years. In phase I, 60 volunteers received single dose QIV (15µg/0.5ml). In phase III, 2320 volunteers were assigned to receive single dose QIV (15µg/0.5ml) or two commercial trivalent influenza vaccines (TIVs) (15µg/0.5ml) in a ratio of 2:1:1. The commercial TIVs were also manufactured by Sinovac Biotech Co., Ltd.
The purpose of this study is to evaluate the safety and immunogenicity of quadrivalent influenza vaccine in healthy subjects aged over 3 years