An ELISPOTassay was used to determine the splenocyte recognition of the corresponding peptides via IFN-c release after animal immunization. The largest number of splenocytes (appeared as spots) was produced in mice after immunization with NP373 and NP458 containing the SCT-DNA constructs (79 and 72 spots, respectively). In contrast, only 14 and 4 spots were observed in animals immunized with NP189 and NP158 containing the SCT-DNA constructs, respectively. The results were very similar to the negative control (5 spots only). The immunogenicity triggered by NP189 in mice was comparatively low when compared with the results of the T2-cell binding assay and the intracellular cytokine staining. Nonetheless, the results indicate that the immunogenicity of NP373 and NP458 was more than 18 times higher than that induced by NP158 (Fig. 4) .