TABLE 1.

Total IgG anti-PA and antispore antibody responses to either PA-FIS or PA alone in the lung mucosal secretions from immunized mice and guinea pigs^a

Animal model	Antigen(s)	Immunization protocol	No. of animals	Anti-PA antibody titer				Antispore antibody titer
				ELISA		TNAb
				Median ± SD	P	Median ± SD	P	Median ± SD	P
Mouse	PA+FIS	(s.c.+i.n.)×3	19	11.70 ± 1.22		6.64 ± 1.52		9.24 ± 1.42
	PA+FIS	i.n.×2	4	9.79 ± 1.91	0.0173*	4.78 ± 1.05	0.0304*	9.79 ± 0.95	NS
	PA+FIS	i.n.×3	10	10.21 ± 0.83	0.0019†	5.76 ± 0.98	NS	9.49 ± 0.67	NS
	PA+FIS	s.c.×2	12	7.56 ± 0.70	0.0001‡	3.60 ± 0.96	0.0001‡	6.75 ± 0.26	0.0001‡
Guinea pig	PA+FIS	(s.c.+i.n.)×3	6	12.24 ± 0.54		5.22 ± 0.97		7.35 ± 0.39
	PA	(s.c.+i.n.)×3	2	11.26 ± 0.41	NS	5.11 ± 1.71	NS
	PA+FIS	i.n.×3	4	8.57 ± 0.31	0.0001‡	3.42 ± 0.13	0.0067†	6.71 ± 0.08	0.0136*
	PA+FIS	s.c.×2	6	11.80 ± 1.28	NS	5.62 ± 0.79	NS	7.06 ± 0.37	NS

^aIn each column of values (ELISA anti-PA, anti-PA TNA, and ELISA antispore), an unpaired Student t test (5%, two-tailed P value) was used to compare the median obtained with each of the protocols (rows) to the median of PA-FIS [(s.c.+i.n.)×3] in the same column. A P value of ≤0.05 was considered to indicate a statistically significant difference. According to the P value, the difference was either significant (*), very significant (†), extremely significant (‡), or not significant (NS). Median ± SD values are log₂ ± the standard deviation. Antibody titers were measured in the BAL fluids from immunized animals as described in Materials and Methods.

^bTNA, lethal TNA titer.