a MDT, mean death time calculated based on the data at
the highest dilution in which all off the embryos had died.b TCID50, 50% tissue culture
infectious dose in MDCK (Madin-Darby canine kidney) cell.
c MLD50, median lethal dose in mice
was expressed as the lgEID50.
d CK-IVPI indicates the intravenous pathogenicity
index in chickens.