Vaccination has been widely used as a procedure for the control of paratuberculosis. Both killed and attenuated vaccines have been employed in several experiments with generally good results. In this work, the cellular (measured by intradermal skin test and gamma-Interferon assay) and humoral (estimated by means of AGID and ELISA tests) responses have been evaluated in lambs and kids vaccinated with an attenuated (Neoparasec(r)) or a killed vaccine (Gudair(r)). These animals constituted the replacement of two flocks of sheep and one of goats with annual losses due to paratuberculosis %gt; 6%. Immune responses followed a similar pattern in both vaccines. Very high cellular and humoral reactions appeared at 15-30 days post vaccination (d.p.v.) which were increasing until 100 d.p.v. From then, a slow decrease was observed until the 300 d.p.v. when the last sampling was performed. A clinical and pathological follow-up was carried out in these flocks for the following two years and no new cases of paratuberculosis were diagnosed. No significant differences were detected either in the immune responses or in the efficiency of the two types of vaccines employed.