Table 2. Mortality in 15-day-old specific pathogen free chickens inoculated with five isolates of IBV.

Group number	Inoculated IBV isolate	Chicken embryo passagea	Dose, median embryo infectious doses (log10)b	Dead chicks (%)c
1	LX4	4	4.2	1
2	LS2	2	4.5	3
3	LD3	3	4.5	2
4	LHI10	10	5.0	2
5	LH2	2	5.0	2
6d	Control

^aDifferent passages used as in Table 1.

^bDose per chick, 200 μl.

^cTen chicks per group.

^dInoculated with 200 μl sterile allantoic fluid per chick.