TABLE 2.

Protective efficacy of mutant S06004ΔSPI2 in chickens

Group	Vaccination			Challenge			No. of survivors/total no. of chickens
	Strain or control	Route	Dose (CFU)	Strain	Route	Dose (CFU)
A	S06004ΔSPI2	Oral	2 × 108	S06004	Intramuscular	1 × 109	10a/10
B	PBS			S06004	Intramuscular	1 × 109	6/10
C	S06004ΔSPI2	Oral	2 × 108	SG9	Intramuscular	1 × 109	10a/10
D	PBS			SG9	Intramuscular	1 × 109	3/10
E	PBS						10/10

^aP < 0.05 for comparison of group A with group B and group C with group D.