Fig. 4.

Replication kinetics of A(H3N2)v influenza viruses in polarized human airway epithelial cells. The seasonal H3N2 viruses are abbreviated as follows: WI/05, A/Wisconsin/67/2005; PE/10, A/Perth/16/2009; RI/10, A/Rhode Island/01/2010; WI/10, A/Wisconsin/13/2010; and HK/09, A/Hong Kong/34341/2009. Calu-3 cells cultured for 1 wk were inoculated with virus at an MOI of 0.01. Culture supernatants were collected at the times indicated, and virus titers were determined by standard plaque assay. The titer value represents the average for three independent wells. Asterisks indicate statistically significant difference between seasonal H3N2 viruses and four A(H3N2)v viruses at 16, 24, 48, and 72 h, based on Mann–Whitney test (each was P < 0.004).