TABLE 1.

Geometric mean SEA-specific cytokine production from all animals (n = 7) during the acute and chronic phases of the primary infection and reinfection

Cytokine	Infection	Geometric mean production (pg/ml) ± SEM inb:
		Acute phase		Chronic phase
		Primary	Reinfection	Primary	Reinfection
IFN-γ	SI	297 ± 32	203 ± 72	28 ± 8	120 ± 42
	MI	291 ± 59	270 ± 61	31 ± 17	190 ± 93
IL-2	SI	85 ± 14	784 ± 173**	119 ± 42	704 ± 316**
	MI	163 ± 51	1,483 ± 186**	242 ± 83	727 ± 124**
IL-4	SI	137 ± 28	251 ± 113*	21 ± 14	173 ± 63*
	MI	62 ± 25	639 ± 217**	20 ± 8	68 ± 31
IL-5	SI	285 ± 52	129 ± 64	17 ± 4	117 ± 46
	MI	31 ± 14	616 ± 76*	219 ± 58	160 ± 57
IL-10	SI	224 ± 38	496 ± 81**	126 ± 61	138 ± 21
	MI	71 ± 41	348 ± 136*	130 ± 55	28 ± 3
TGF-β	SI	1,141 ± 217	1,850 ± 261**	767 ± 164	1,712 ± 312*
	MI	751 ± 192	2,852 ± 310***	862 ± 250	1,785 ± 351*

^aSI, single primary infection of 1,000 cercariae; MI, multiple primary infections of 100 cercariae per week for 10 weeks. All animals were reinfected singly with 1,000 cercariae after treatment. 

^bAcute-phase results are peak cytokine responses at either 6 or 9 weeks in each animal after primary or secondary infection. Chronic-phase results are peak cytokine responses at 19 weeks in the primary infection and at either 13 or 16 weeks after reinfection. Asterisks indicate a significant difference compared to primary infection (∗, P < 0.05; ∗∗, P < 0.01; ∗∗∗, P < 0.001).