TABLE 2.

Comparison of oral vaccine experiments

Characteristic	Value for experiment:		P value
	1 (EcLigA7-13 10/i.p.)	2 (EcLigA7-13 40/i.d.)
LigA7-13 dose (mg)	37	148
Challenge route	i.p.	i.d.
Challenge dose (no. of leptospires)	1,000	100
Challenge dose (no. of leptospires)/ED50	50	10
No. of control-immunized animals	8	8
No. of LigA7-13-immunized animals	8	8
% survival for control immunized	0	0
% survival for LigA7-13 immunized	37.5	62.5
ELISA Lc (OD450)a	0.236	0.427
Mean LigA antibody levels (OD450) (all animals) after:
2nd wk	0.539	0.688	NSb
3rd wk	0.432	1.491	<0.05
4th wk	0.499	1.337	<0.03
Mean LigA antibody levels (OD450) (survivors) after:
2nd wk	1.244	1.035	NS
3rd wk	1.066	2.162	NS
4th wk	1.077	1.774	NS

^aThe critical limit (Lc) is defined as the signal that indicates that the target is present (rejection of the null hypothesis): 1.65 SD over the mean of background signals.

^bNS, not significant.