Figure 5

N. caninum-specific humoural immune responses. Serum levels of total IgG (A), IgG1 (B) and IgG2 (C) antibodies against N. caninum in G-Control, G-NcSpain7 and G-NcSpain1H. Immunoglobulin levels are expressed as a relative index percent (RIPC) according to RIPC = (OD₄₀₅ sample − OD₄₀₅ negative control)/(OD₄₀₅ positive control − OD₄₀₅ negative control) × 100. Each point represents the mean + SD at different sampling times. The red line indicates the ELISA cut-off point from which samples are considered positive. **** and ** indicate P < 0.0001 and P < 0.001 significant differences.