TABLE 2.

Serum antibody responses induced by rUre immunization

Routea	Vaccineb	Challengec	Mean leveld (μg/ml) in serum of:		IgG1/IgG2a ratio	Mean level of IgAd (μg/ml) in serum
			IgG1	IgG2a
p.o.	rUre + LT	−	30.57	183.70	0.16	1.86
		+	20.72	83.51	0.25	1.69
r.	rUre + LT	−	220.60	88.04	2.51	18.34
		+	121.92	139.09	0.88	38.48
i.n.	rUre + LT	−	120.40	416.50e	0.29	0.64
		+	85.06	1,017.87e	0.08f	3.17
All	LT	+	0.42	0.92	0.45	0.13

^aWeekly immunizations were given on days 0, 7, 14, and 21 by either the p.o. (50 μl of soluble antigen delivered by pipette into the buccal cavity), the i.n. (5 μl of soluble antigen delivered to each external naris of unanesthetized mice), or the rectal (r.) (25 μl of soluble antigen delivered with an olive-tipped catheter) route. Sham-immunized control animals (n = 15) received LT alone by either the p.o., i.n., or rectal route, and results were pooled for this analysis (“All”). 

^bBy the p.o. or rectal route, animals were administered 25-μg doses of rUre plus LT (5 μg p.o. and 25 μg rectally), and by the i.n. route, animals were administered 10-μg doses of rUre plus LT (5 μg) (n = 10/group). 

^cAnimals were challenged once with 100 μl of a 10⁸-CFU/ml suspension of streptomycin-resistant H. pylori X47-2AL. 

^dSerum antibody measurements are presented as geometric means. 

^eStatistical significance (P < 0.05) was determined by the Wilcoxon rank sum test by comparing levels of IgG1 to those of IgG2a. 

^fStatistical significance (P < 0.05) was determined by the Wilcoxon rank sum test by comparing results for challenged animals to those for similarly treated unchallenged animals.