Table 1.

Scores of host immune response levels in age-matched pigs with primary and secondary immune responses.

		Humoral immunity							Cell-mediated immunity
		Faeces SIgA		Ileum SIgA	Serum IgA		Serum IgG		IFN-γ
Group	Pig #*	d11-48	d67-75	d83/84	d6-48	d67-75	d6-48	d67-75	d11-48	d60-82
RE	37	+	++	+	++	++	+	+	+	++
RE	38	+	+		++	+	++	++	+	++
RE	52	+	++	++	+	++	+	++	+	++
RE	55	+	++	++	+	++	+	++	+	++
RE	57		+		+	+	++	++	+	++
RE	26	+	+	+	+	+	+	++	+	++
RE	39		+	+	+	+	+	+	+	++
RE	53	+	+		+		+	++	+	++
RE	61	+	++		+	+	++	+	+	++
RE	64		+		+	+		+	+	++
CC	36		++			+		++		+
CC	44			+		++		++		+
CC	51		++			++		++		++
CC	58		+	++		+		++	+	+
CC	59		+	+		++	+	++		+
CC	66	+	++	++		++		++		++
CC	70		+	+		++		++		+

The level of response for L. intracellularis-specific IgA in faeces and ileum content, IgA and IgG in serum, and antigen-specific IFN-γ-production in whole blood cultures were scored for individual pigs from the RE group and the CC group. Summed scores for the primary and secondary infection periods are categorised as: no response (BLANK), low-medium response (+), high response (++). * All pigs in the RE group were protected against re-infection as defined by: absence of bacterial shedding and serum acute phase protein response as well as low or no IHC score at termination of the experiment (see Result section and [6]).