aSPF chickens (n = 5) were inoculated intranasally 107 EID50 of each virus. Clarified homogenates of tracheas and lungs from three animals collected on 5 dpi were titrated for virus infectivity in SPF embryonated chicken eggs from initial dilutions of 1:10. Virus titers were expressed as mean log10EID50/g wet tissues ± standard deviation (SD). Two chickens were observed for signs of lethality, and seroconversion was confirmed by hemagglutination inhibition (HI) assay on 14 dpi. *P < 0.05 compared with rSD01.