TABLE 2.

Immunizations, isolation of challenge strains from organs, and mortality after challenge

Group	Immunizationa		Challenge
			Mortality (%)	Isolation of challenge strainb
	Prime	Booster		No. of infected livers/no. of livers tested	No. of infected spleens/no. of spleens tested
A	JOL911	None	10	80	2/2	2/2
B	JOL911	JOL911	10	60	1/4	1/4
C	JOL906	None	10	40	4/6	4/6
D	JOL906	JOL906	10	30	3/7	3/7
E	4 parts JOL911 and 1 part JOL906	JOL911	10	0	0/10	0/10
F	4 parts JOL911 and 1 part JOL906	4 parts JOL911 and 1 part JOL906	10	30	2/7	2/7
G	PBS	PBS	10	100	ND	ND

^aJOL911 is a vaccine strain, and JOL906 is an LTB protein-secreting strain. The total number of inoculated bacterial cells per dose for all animals was 2 × 10⁹ CFU in a volume of 20 μl.

^bND, not detected.