Dynamic Changes of the Hemagglutination-Inhibition Titers against the 2009 A/H1N1 Virus after Administration of the 2009 A/H1N1 Influenza Vaccine.

<p>Seroprotection is defined as HI titer of 1∶40 or more. Seroconversion is defined as postvaccination HI titer of 1∶40 or more, increasing at least four times. GMT = geometric mean titer. HI titers below 1∶10 were assigned a value of 1∶5, in calculating the geometric mean titer.</p><p>*(p<0.05) and</p><p>**(p<0.001) represent the statistical significances compared with the pre-vaccination values (day 3 value for seroconversion rate). The Pearson's chi-squared test was used for the seroprotection and seroconversion rate analysis, the two-way Student's t-test for the GMT analysis. Pre: pre-vaccination.</p

Dynamic Changes of the Hemagglutination-Inhibition Titers against the Seasonal H1N1 Virus after Administration of the 2009 A/H1N1 Influenza Vaccine.

<p>Dynamic Changes of the Hemagglutination-Inhibition Titers against the Seasonal H1N1 Virus after Administration of the 2009 A/H1N1 Influenza Vaccine.</p

ELISA to detect specific anti-HA IgG antibody at different time points in the sera of volunteers for the 2009 A/H1N1 influenza vaccine administration.

<p>The OD450 nm on different days were measured and results were displayed as ΔOD450 nm with each prevaccination (baseline) OD subtracted in every subject's serial samples. "pre": pre-vaccination. The OD value of the pre-vaccination sera was 0.76±0.06 (IgG baseline). The blank OD (no sera added) of the ELISA was 0.05. **: p<0.001, two-way Student's t-test.</p

Geometric Mean HI Titers against the 2009 A/H1N1 Influenza Virus in Two Groups of People with Different Seasonal Influenza Antibody Levels.

†<p>Individuals with prevaccination seasonal influenza HI titer ≥1∶40.</p><p>° Individuals with prevaccination seasonal influenza HI titer <1∶40.</p><p>*(p<0.05) and</p><p>**(p<0.001) represent the statistical differences between the two groups, two-way Student's t-test.</p

Geometric Mean HI Titer against the Seasonal and the 2009 A/H1N1 Influenza Virus in Two Groups of Mice with Different Vaccination Procedures^#.

#<p>Group A: mice immunized with PBS (control) on day 0 and the 2009 A/H1N1 influenza vaccine on day 21; Group B: mice immunized with the 2008-09 trivalent seasonal influenza vaccine on day 0 and the 2009 A/H1N1 influenza vaccine on day 21.</p><p>Seasonal: geometric mean HI titer against the 2008-09 trivalent seasonal influenza vaccine; 2009 A/H1N1: geometric mean HI titer against the 2009 A/H1N1 pandemic influenza vaccine.</p><p>**(p<0.001) represents the statistical differences between Group A and Group B (two-way Student's t-test).</p