Fig. 1.

Influenza A virus-specific humoral immunity. The proportion of children of the healthy unvaccinated control group (gray bars) and the vaccinated group of children with CF (white bars) with antibodies against at least one of the influenza viruses was calculated for all influenza viruses of each subtype (A) or for all indicated viruses individually (B). Bars represent percentages with 95% confidence intervals. (C) GMTs were calculated for all samples in which antibodies against the indicated viruses were detected. Bars represent GMTs with standard deviations, and the horizontal gray bar indicates the detection limit of the assay. The asterisks indicate significant differences between the two groups (P < 0.05).