Correlation of antibody titers specific for seasonal vaccine strains and pandemic viruses after seasonal vaccination.

<p>Serum samples were collected on 21 days after administration of 2009–2010 inactivated unadjuvanted trivalent influenza vaccine (TIV) in US healthy adults and elderly. An HAI assay was performed using 0.5% turkey erythrocytes. A correlation analysis between seasonal strain specific HAI titers and pandemic strain specific HAI titers was performed using nonparametric Spearman's ρ test by JMP Version 7. The scatterplots of HAI titers are shown in the presence of 95% bivariate normal density ellipses (indicating the distribution of 95% of individual data points plotted) and corresponding <i>p</i> values. A, A/California/07/2009 (H1N1) vs A/Uruguay/716/2007 (H3N2); B, A/South Carolina/18/2009 (H1N1) vs A/Uruguay/716/2007 (H3N2).</p

Hemagglutination inhibition (HAI) titers against 2009 pandemic H1N1 viruses.

<p>Serum samples collected from US healthy volunteers vaccinated with 2009–2010 inactivated unadjuvanted trivalent influenza vaccine (TIV) were tested for cross-reactivity against 2009 pandemic H1N1 viruses by HAI assay using 0.5% turkey erythrocytes. The pandemic influenza specific seroprotection rates (the proportion of subjects having an HAI titer ≥40) before and 21 days after TIV administration and the seroconversion rates (the proportion of subjects having a ≥4-fold rise in HAI titers) were plotted according to the age distribution of vaccinees for A/California/07/2009 (H1N1) (A and F), A/Iraq/8529/2009 (H1N1) (B and G), A/Ontario/RV3226/2009 (H1N1) (C and H), A/South Carolina/18/2009 (H1N1) (D and I) and A/England/195/2009 (H1N1) (E and J), respectively. * indicates the corresponding seroconversion rate in panel F, G, H, I, and J.</p

Hemagglutination inhibition (HAI) titers against 2009–2010 seasonal vaccine strains.

<p>Serum samples collected from US healthy volunteers vaccinated with 2009–2010 inactivated unadjuvanted trivalent influenza vaccine (TIV) were tested by HAI assay using 0.5% turkey erythrocytes. The geometric mean titers (GMTs), the seroprotection rates (the proportion of subjects having an HAI titer ≥40) before and 21 days after TIV administration, and the seroconversion rates (the proportion of subjects having a ≥4-fold increase in HAI titers) were plotted according to the age distribution of vaccinees for A/Brisbane/59/2007 (H1N1) (A and D), A/Uruguay/716/2007 (H3N2) (B and E), and B/Brisbane/60/2008 (C and F), respectively. The 95% CI for individual HAI GMTs are shown as error bars. The dotted lines indicate HAI titer of 40.</p

Severe pneumonia and pathogenic damage in human airway epithelium caused by Coxsackievirus B4

Coxsackievirus B4 (CVB4) has one of the highest proportions of fatal outcomes of other enterovirus serotypes. However, the pathogenesis of severe respiratory disease caused by CVB4 infection remains unclear. In this study, 3 of 42 (7.2%, GZ-R6, GZ-R7 and GZ-R8) patients with severe pneumonia tested positive for CVB4 infection in southern China. Three full-length genomes of pneumonia-derived CVB4 were sequenced and annotated for the first time, showing their high nucleotide similarity and clustering within genotype V. To analyze the pathogenic damage caused by CVB4 in the lungs, a well-differentiated human airway epithelium (HAE) was established and infected with the pneumonia-derived CVB4 isolate GZ-R6. The outcome was compared with that of a severe hand-foot-mouth disease (HFMD)-derived CVB4 strain GZ-HFM01. Compared with HFMD-derived CVB4, pneumonia-derived CVB4 caused more intense and rapid disruption of HAE polarity, leading to tight-junction barrier disruption, loss of cilia, and airway epithelial cell hypertrophy. More pneumonia-derived CVB4 were released from the basolateral side of the HAE than HFMD-derived CVB4. Of the 18 cytokines tested, only IL-6 and IL-1b secretion significantly increased on bilateral sides of HAE during the early stage of pneumonia-derived CVB4 infection, while multiple cytokine secretions significantly increased in HFMD-derived CVB4-infected HAE. HFMD-derived CVB4 exhibited stronger neurovirulence in the human neuroblastoma cells SH-SY5Y than pneumonia-derived CVB4, which is consistent with the clinical manifestations of patients infected with these two viruses. This study has increased the depth of our knowledge of severe pneumonia infection caused by CVB4 and will benefit its prevention and treatment.</p