FIG. 1.

Plots showing the IC₅₀ (in nM) ranges of oseltamivir for avian, swine, and human influenza viruses of the N1 NA subtype. Isolates are ranked in order by the IC₅₀. Sixty-two duck, 25 shorebird, 4 gull, and 15 swine isolates and 14 human seasonal influenza viruses were analyzed. Mean IC₅₀s between the four types of hosts were analyzed using a Kruskal-Wallis test and Dunn's multiple comparison post hoc test. The groups designated with the same letter (either a or b) did not differ significantly (P > 0.05). The groups designated with different letters differed significantly (P < 0.05).