TABLE 3.

Peak S. flexneri 2a LPS-specific ASC responses as a function of proteosome S. flexneri 2a LPS vaccine dose

Size of dose (mg)	Peak IgA ASC countsa				Peak IgG ASC countsa				Peak IgM ASC countsa
	Geometric meanb	95% CIe	Median	% Responsed	Geometric mean	95% CI	Median	% Response	Geometric mean	95% CI	Median	% Response
Predose	0.4	0.2–0.6	0	0	0.1	0–0.2	0	0	0.2	0.1–0.3	0	0
0.1	4.8c	1.4–24.9	3.0	40	2.2c	0.1–8.4	2.0	40	2.1c	1.2–3.4	2.0	0
0.4	7.6c	2.8–18.9	6.0	60	4.3c	0.7–16.1	2.0	40	2.7	0.1–8.3	1.0	30
1.0	20.2c	8.0–46.2	22.5	90	13.7c	4.7–37.2	16.5	80	6.8c	4.2–10.7	1.0	70
1.5	26.4c	11.0–61.5	31.0	90	16.2c	5.8–42.8	22.0	80	8.2c	3.0–20.8	7.0	70

^aAll counts are based on peak values at any time postimmunization for each individual in each dose group and are expressed as specific ASCs per 10⁶ PBMCs. 

^bZero values were accommodated by adding 1 to all data, calculating geometric means and 95% confidence interval, and then subtracting 1 from results. A linear ascending trend of geometric mean with vaccine dose is detected for each antibody isotype: P < 0.01 for IgA: P < 0.03 for IgG and IgM. 

^cSignificantly different from preimmunization values by paired sample t test (P < 0.05; P < 0.001 for all isotypes in the 1.0- and 1.5-mg-dose groups). 

^dPercentage of subjects attaining ASC levels exceeding four specific ASCs per 10⁶ PBMCs, the 99th percentile of the day 0 distribution (see text). 

^eCI, confidence interval.