Observation on immunogenicity of pandemic influenza A (H1N1) vaccine and its persistence among students

Objective To understand the immunogenicity of pandemic influenza A (H1N1) vaccine and its persistence among students and provide scientific evidence for the future use of pandemic influenza A (H1N1) vaccine and development of immunization strategies. Methods The middle school students in Xiuzhou were selected on basis of informed consent, the students were given a injection of H1N1 vaccine manufactured in China. The blood samples were taken from them before vaccination and at 1, 3, 6 months and I year after vaccination to detect HI antibodies to pandemic influenza A (H1N1) virus at different phases. Results The positive rate of HI antibody was 35.68% among the students before vaccination. The positive conversion rate of HI antibody was 75.14% and the positive rate was 92.43% one month after vaccination. The GMT (reciprocal) was 177.42, an increase of 9.32 times. The antibody conversion rate remained to be 84.21% and the GMT (reciprocal) was 93.03 one year after vaccination, Conclusion The domestic H1N1 vaccine has good immunogenicity which can last for long time. There is no need to re-vaccinate one year later.