Skip to main content


Figure 3 | BMC Research Notes

Figure 3

From: Amino acid substitutions in hemagglutinin of the 2009 pandemic influenza A(H1N1) viruses that might affect the viral antigenicity

Figure 3

Antibody titers against the 2009 pandemic influenza A(H1N1) viruses. The H1N1pdm antibody positive convalescent sera collected during Thailand’s 2009 pandemic influenza outbreaks, wave 1 (A), wave 2 (B), and wave 3 (C), were tested against 11 isolates of 2009 pdmH1N1 viruses by HI assay. Stacked bars show the proportion of samples with different HI titers, while the line denotes the geometric mean titer (GMT). *represents a statistically lower GMT compared with the GMT of viruses isolated from the same epidemic wave as sera, **represents a statistical difference between the GMT of BKK4 and BKK5, p < 0.05, tested by Wilcoxon Signed Ranks Test.

Back to article page