Figure 1

Replication kinetics of mouse-adapted virus.
(A) Cells were infected with four influenza B viruses and mouse-adapted viruses at a multiplicity of infection55 of 0.001. Cell culture supernatants were collected at 12, 24, 48 and 72 hours post infection and viral titers were measured in units of log10 TCID50/mL. (B) Determination of plaque phenotype. *indicates P < 0.0001 and †indicates P < 0.001 compared with the P0 (B/Florida/04/06). The error bars show the standard errors of the mean (SEMs), which were derived from three independent experiments.