Ices to protect this age group from both the new and conventional seasonal influenza should be carried out.Except for the 0? age group and a special case of .60 age in A/H1N1 influenza, all other age groups showed significantly decreased Fexinidazole Antibody levels of A/H1N1 during the 2009 H1N1 pandemic compared to before the pandemic, using t-test. doi:10.1371/journal.pone.0053847.tAnalysis of the Trend of Influenza Incidences in Shenzhen,We obtained the statistics of 220,883 influenza-like illness (ILI) cases in Shenzhen 2009 from study subjects II. The number of incidences is plotted on a month-by-month basis in Figure 1. The peak of ILIs occurred in July 2009, sharply declined afterwards, and formed a new wave in November. This could partially explain the significant drop of the three seasonal influenza antibody titer levels in September compared to March, but it could not explain the high level of A/H1N1 in September. From Study Subjects II, there are 5,125 incidences by influenza JI-101 price subtypes (Figure 2). It 18325633 shows that the 2009 H1N1 pandemic peaked in September and dominated all ILIs in October. Moreover, the seasonal H1N1 incidences dropped off to a very low level in September. This fact, combined with the unusually high level of seasonal H1N1 antibody in September, implies that the seasonal H1N1 influenza antibody might have been present in swine H1N1-infected cases, and could have been 26001275 associated with the 2009 H1N1 antibody. The seasonal H1N1 antibody was therefore persistent during the pandemic peak of the 2009 H1N1 but after the peak of its own antigen.Antibody Titer Change by Gender GroupsA comparison between gender groups was performed on the March and September data on Study Subjects I (In the remaining parts of the paper, all the analysis and results were based on Study Subjects I.) There was no significant difference between the seroprevalence in males and females in March or in September. All types of seasonal influenza antibodies significantly decreased inMultivariate Analysis of the Relationship of sH1N1 Antibody Titer value, Gender, Age and Seasonal Influenza Antibody Titer ValueA multivariate analysis was performed using all Study Subjects I whose 2009 H1N1 HI antibody values were available. 2009 H1N1 antibody titers were used as response variable; gender, age and 4 seasonal influenza antibody titers were used as independent variables. All antibody titer values were in log transformed scale. Consistent with previous analysis, the result showed that seasonalTable 7. Change of A/H3N2 Antibody Titer Level Between March and September by Age Group (mean titer value in log2 scale).Age group/Group mean in log2 scale 0? March September Difference P-value Bonferroni Adjusted P-value 3.590 3.625 20.035 0.8056?5 3.709 2.884 0.825 1.6061016?5 3.878 3.260 0.618 1.26?9 3.772 3.204 0.567 1.60 3.966 3.640 0.326 0.0618 0.5.5.Except for the 0? age group, all other age groups showed significantly decreased antibody levels of A/H3N2 during the 2009 H1N1 pandemic compared to before the pandemic, using t-test. doi:10.1371/journal.pone.0053847.tInfluenza Antibodies Reaction during 2009 H1NTable 8. Change of B/Yamagata Antibody Titer Level Between March and September by Age Group (mean titer value in log2 scale).Age group/Group mean in log2 scale March September Difference P-value Bonferroni Adjusted P-value0? 3.273 3.561 20.288 0.0316 0.6?5 3.741 2.983 0.759 1.2361026 6.16?5 4.945 3.662 1.283 6.91610215 3.26?9 4.562 3.461 1.101 1.02610211 5.60 4.491 3.80.Ices to protect this age group from both the new and conventional seasonal influenza should be carried out.Except for the 0? age group and a special case of .60 age in A/H1N1 influenza, all other age groups showed significantly decreased antibody levels of A/H1N1 during the 2009 H1N1 pandemic compared to before the pandemic, using t-test. doi:10.1371/journal.pone.0053847.tAnalysis of the Trend of Influenza Incidences in Shenzhen,We obtained the statistics of 220,883 influenza-like illness (ILI) cases in Shenzhen 2009 from study subjects II. The number of incidences is plotted on a month-by-month basis in Figure 1. The peak of ILIs occurred in July 2009, sharply declined afterwards, and formed a new wave in November. This could partially explain the significant drop of the three seasonal influenza antibody titer levels in September compared to March, but it could not explain the high level of A/H1N1 in September. From Study Subjects II, there are 5,125 incidences by influenza subtypes (Figure 2). It 18325633 shows that the 2009 H1N1 pandemic peaked in September and dominated all ILIs in October. Moreover, the seasonal H1N1 incidences dropped off to a very low level in September. This fact, combined with the unusually high level of seasonal H1N1 antibody in September, implies that the seasonal H1N1 influenza antibody might have been present in swine H1N1-infected cases, and could have been 26001275 associated with the 2009 H1N1 antibody. The seasonal H1N1 antibody was therefore persistent during the pandemic peak of the 2009 H1N1 but after the peak of its own antigen.Antibody Titer Change by Gender GroupsA comparison between gender groups was performed on the March and September data on Study Subjects I (In the remaining parts of the paper, all the analysis and results were based on Study Subjects I.) There was no significant difference between the seroprevalence in males and females in March or in September. All types of seasonal influenza antibodies significantly decreased inMultivariate Analysis of the Relationship of sH1N1 Antibody Titer value, Gender, Age and Seasonal Influenza Antibody Titer ValueA multivariate analysis was performed using all Study Subjects I whose 2009 H1N1 HI antibody values were available. 2009 H1N1 antibody titers were used as response variable; gender, age and 4 seasonal influenza antibody titers were used as independent variables. All antibody titer values were in log transformed scale. Consistent with previous analysis, the result showed that seasonalTable 7. Change of A/H3N2 Antibody Titer Level Between March and September by Age Group (mean titer value in log2 scale).Age group/Group mean in log2 scale 0? March September Difference P-value Bonferroni Adjusted P-value 3.590 3.625 20.035 0.8056?5 3.709 2.884 0.825 1.6061016?5 3.878 3.260 0.618 1.26?9 3.772 3.204 0.567 1.60 3.966 3.640 0.326 0.0618 0.5.5.Except for the 0? age group, all other age groups showed significantly decreased antibody levels of A/H3N2 during the 2009 H1N1 pandemic compared to before the pandemic, using t-test. doi:10.1371/journal.pone.0053847.tInfluenza Antibodies Reaction during 2009 H1NTable 8. Change of B/Yamagata Antibody Titer Level Between March and September by Age Group (mean titer value in log2 scale).Age group/Group mean in log2 scale March September Difference P-value Bonferroni Adjusted P-value0? 3.273 3.561 20.288 0.0316 0.6?5 3.741 2.983 0.759 1.2361026 6.16?5 4.945 3.662 1.283 6.91610215 3.26?9 4.562 3.461 1.101 1.02610211 5.60 4.491 3.80.
