The L. intracellularis specific antibodies, especially IgA, induced by vaccines are thought to be important in mediating protection against infection of enterocytes by L. intracellularis and efforts to bolster the IgA in the ileal mucosa by feed supplementation with short-chain fructo-oligosaccharide have shown improved protection against L. intracellularis [15, 34]. Here, CD79A is linked to infection.