TABLE 3.

S. sonnei LPS-specific immune responses in naive controls after subsequent S. sonnei 53G challenge

Volunteer serial no.	53G sheddinga (no. of days)	ASC count/106 PBMCsb			Fold increase in serum Ab titersc			Fold increase in fecal IgA titers/100 μg of T-IgAc	Clinical symptoms related to challenge
		IgA	IgG	IgM	IgA	IgG	IgM
1	5	2,930	2,810	1,310	15	5			Fever
2	2	6,450	6,760	3,180	13	7
3	3	1,880	4,770	369	13				Myalgia, fatigue, malaised
4	5	2,340	5,140	93	11	7
5	5	4,390	4,630	1,070	42	23			Shigellosis
6	6	920	620	170	44	43	5
7	7	1,030	1,150	350	226	50	20		Vomit, diarrhea
8									Dysentery
9								4	Fevere
10

^aNumber of days of shedding based on culture and/or PCR of fecal sample.

^bOnly ASC counts of ≥5 ASCs per 10⁶ PBMCs are shown.

^cA ≥4-fold increase in antibody titers was considered significant. Ab, antibody.

^dControl 3 had AE but did not meet the criteria for clinical endpoint (diarrhea, dysentery, fever, or shigellosis).

^eControl 9 had IgG and IgM ASC responses to S. sonnei Invaplex (data not shown).