TABLE 3.

Immune responses of BALB/c mice (n = 5) to either two (formulations 2, 4, 5, and 6) or three (formulations 1 and 3) 10-μg i.m. doses of rPA given as microencapsulated formulations on days 1 and 21 (two-dose regimen) and on days 1, 21, and 111 (three-dose regimen)

Formulation	Anti-rPA IgG titera
	Day 28	Day 42	Day 85	Day 120
1	NDb	1.7	2.3	3.54 ± 0.42
2	4.57 ± 0.18	4.45 ± 0.25	4.02 ± 0.12	3.42 ± 0.2
3	2.6	2.0	2.0	2.93 ± 0.23
4	4.26 ± 0.06	4.45 ± 0.15	3.96 ± 0.11	3.42 ± 0.07
5	3.2 ± 0.1	3.77 ± 0.34	3.0 ± 0.2	3.3 ± 0.17
6	ND	ND	ND	ND

^aThe titers are mean log₁₀ reciprocal serum dilutions ± standard errors of the means; single values are titers obtained from single responding animals. The titers were determined on days 28, 42, 85, and 120 after the primary immunization.

^bND, not detectable.