The applicability of some assay to evaluate the effectiveness of immune function, as previously used in other animal species (pigs, cows and shhep), was tested in an alpaca (Lama pacos) herd affected by Caseous Lymphadenitis (Corynebacterium pseudotuberculosis) and subject to a vaccination programme against the causative agent. The vaccination programme was initiated following failure of controlling the outbreak by isolation and treatment of the initially infected animals. An homotypic, autogenous inactivated and adjuvated (aluminium hydroxide) vaccine, administered subcutaneously at day 0 (A) and after 21 days (B) was used. Blood samples were collected by venipuncture of the jugular vein on days 0, 21 and 42 (C) and serum obtained from these whole blood samples was tested for: Lysozyme serum titratio (expressed in microg/ml), serum Bactericidial assay (expressed in %) , semiquantitative complement titration (expressed in CH50) and IgGs concentrations (by Radial immunodifusion test).