Growth and pathogenicity of H5N1 viruses

aAll data are the mean±SD from three independent experiments.
b90–100% mortality in groups of 10 mice after intranasal inoculation with virus dose of 103 EID50 was considered as high pathogenicity; no mortality and disease signs after infection with similar virus dose was considered as low pathogenicity.
cSevere systemic disease with mortality developed after intranasal infection with virus dose of 106 EID50 was considered as high pathogenicity; severe respiratory disease without mortality was considerate as moderate pathogenicity, and mild or asymptomatic respiratory infection without mortality as low pathogenicity.
dIntravenous pathogenicity tests [46] with all viruses killing 100% of inoculated chickens indicative of HPAI viruses.