ABSTRACT
Objective To find the changes of haemagglutination inhibition ( HI ) antibody level against A/California/07/2009 (H1N1) within one month after pandemic A/H1N1 influenza vaccine (A/H1N1InfV) vaccination, and to provide data for drawing up immunization protocols against novel influenza . Methods The HI antibodies against A/California/07/2009 (H1N1) in sera from the inoculated subjects were tested by HI test .The geometric mean titer ( GMT) , geometric mean increase ( GMI) , seroconversion (SC) rate, seroprotection (SP) rate of HI antibodies were compared among the sera collected on day 3, 7, 14, 30 post vaccination .Results 961 participants were injected with A/H1N1InfV.In subjects aged 3 to 11 years, the antibody level peaked on day 14 post vaccination, but neither on day 14 nor on day 30, the lower bound of the two -sided 95%CI for the SP rate could fulfill the criteria of the FDA for influenza vac-cine.In subjects aged 12 to 60 years, the antibody level peaked on day 14 post vaccination and the SC rate , SP rate and GMI fulfilled the criteria of the European Medicines Agency ( EMEA) and the FDA for influenza vaccine. In subjects aged more than 60 years, the antibody level peaked on day 30 post vaccination , and the SC rate, SP rate and GMI on day 30 fulfilled the criteria of the EMEA and the FDA .Conclusion One dose A/H1N1InfV vaccination was able to induce enough protection on day 14 for subjects aged 12 to 60 years, on day 30 for subjects aged more than 60 years;however , for subjects aged 3 to 11 years who were antibody-negative at baseline , the lower bound of the two-sided 95%CI for the SP rate on day 14 and day 30 couldn′t fulfill the criteria of the FDA for influenza vaccine .
ABSTRACT
Objective To evaluate the epidemiological effects of vaccine immunization program related to A(H1N1)influenza in the middle school students.Methods Non-randomized clinical trial was designed to assess the A(H1N1)influenza vaccine on its efficacy.14883 students from 8 middle schools in Zhejiang province were recruited and classified into vaccinated or control groups,based on the status of immunization with A(H1N1)influenza vaccine.All subjects were followed up through one epidemic period(6 months)and the incidence rates of influenza-like illnesses,A(H1N1)influenza,and seasonal influenza in these two groups were compared to evaluate the efficacy of the vaccine.Results There were 6334 subjects in the vaccinated group and 8549 in the control group.7441.75 person-years were followed from these two groups.The incidence rate of A (H1N1)influenza in vaccinated group was 1.64‰ per person-year,lower than that of the control group.The rate difference(RD)was-1.64‰ per person-year(95% confidence interval value from-3.04‰ to-0.23‰ per person-year),and the difference was significant(P=0.010).The incidence rate of influenza-like illnesses in vaccinated group was 21.47‰ per person-year,lower than that of the control group(22.69‰ per person-year)and the diffefence was not significant(P>0.05).The incidence rate of B influenza in vaccinated group was 6.63‰ per person-year,higher than that of control group(7.02‰ per person-year)but the difference was not significant(P>0.05).Conclusion This vaccine demonstrated a good epidemiological effect against the A(H1N1)influenza virus infection,observed through a student-immunization program.The cross-protection effect against the influenza-like illnesses and other seasonal influenzas was not noticed in this study.
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Objective To evaluate the safety and epidemiological effects on the first mass vaccination program, using the China-made A (H1N1) influenza vaccine. Methods Descriptive epidemiology and cohort study design were used to assess the influenza A H1N1 vaccine on its safety and epidemiological effects. Results 95 244 subjects were immunized with A (H1N1) influenza vaccine. 193 adverse events were reported through AEFI Management System, with the Reported rates after immunization was carried out. Of 81 adverse reactions confirmed to be related to immunization,reported through the AEFI Management System. The epidemiological protection rate of A (H1N1)influenza vaccine showed a similar safety profile to seasonal flu vaccine. The vaccine demonstrated a good epidemiological effects against A (H1N1) influenza virus infection.