ABSTRACT
Objective To evaluate the immunogenicity and safety of a split-virion influenza vac-cine after its manufacturing process was improved. Methods The immunological non-inferiority of trial to control vaccines was evaluated in 240 subjects aged 3-<18 years. Another 360 subjects aged 18-<60 years were randomly divided into three groups that were respectively given three consecutive lots of trail vaccine to assess the consistency of immunogenicity. Results There were 4. 17% of the subjects aged 3-<18 years showed adverse reactions following immunization with trail vaccine and it was not significantly different from that of the control group (P>0. 05). No significant difference in seroconversion rate, geometric mean titer (GMT) of haemagglutination inhibition antibodies(HIAb) or protection rate was found between trial and control groups (P>0. 05). No significant difference in seroconversion rate or HIAb GMT was found among the three lots (P>0. 05). Conclusion The trial influenza vaccine has good safety, immunogenicity and lot-to-lot consistency after the manufacturing process was improved.