TABLE 2.

Spleen colonization in mice immunized with WR201 and challenged 9 weeks later intranasally with 16M^a

Experiment	No. of weeks after infection	No. infected/no. challenged after immunization with:		P valueb
		Saline	WR201
C	1	2/5	1/5	0.99c
	2	5/5	2/5	0.17c
B	2	4/5	1/4	0.21c
E	4	6/7	2/8	0.041
D	4	8/10	2/10	0.023
	8	6/10	4/10	0.66c
	13	8/10	4/10	0.17c
A	8	15/15	2/15	<0.001
	12	14/15	7/15	0.014

^aMice were immunized with WR201 or sham immunized with saline and challenged with 10⁴ CFU of 16M intranasally. Animals were euthanized at various times after infection for determination of number of splenic bacterial CFU. Limit of detection = 2 CFU. 

^bFisher's exact test. 

^cNot significant.