Fig. 1From: Protective efficacy of an inactivated vaccine against H9N2 avian influenza virus in ducksViral titer of oropharyngeal swabs collected from ducks infected with different H9N2 viruses. Ducks were intravenously inoculated with 106 EID50 of SH441 or SH1753. The virus titers (EID50) were determined for oropharyngeal swabs collected from infected ducks. The PBS-inoculated group was used as controls. The horizon line represents the mean valueBack to article page