Pathotyping and replication of intravenously administrated H7N9/PR8 transfectant virus in chickensa.

aGroups of chicken were infected i.v. with 0.2 ml of 1∶10 dilution of stock virus.bOropharyngeal and Cloacal swabs were collected for virus titration on day 3 after inoculation. A mean value of 1.0 was considered for calculation if virus was not isolated from a swab.cChickens were bled at 2 weeks after inoculation. Sero-conversion was confirmed and analyzed.