Fig. 2

Growth properties of influenza A virus in Calu-3 cell line. The viruses were A/Zhejiang/DTID-ZJU01/2013(H7N9) (H7N9-HU), A/chicken/Zhejiang/1/2013(H7N9) (H7N9-CK), A/Hong Kong/415742/2009(H1N1) (H1N1) and A/Vietnam/1194/2004(H5N1) (H5N1). The experiment was performed in triplicate. Data were shown as mean ± standard error of mean. * indicates P < 0.05 when comparing H7N9-HU with H7N9-CK