Co-administration of attenuated Mycoplasma hyopneumoniae 168 strain with bacterial DNA enhances the local and systemic immune response after intranasal vaccination in pigs

► We co-administrated Mycoplasma hyopneumoniae vaccine with bacterial DNA containing CpG motifs to pigs by intranasal route. ► We examine changes in the level of local and systemic immune response. ► The level of local respiratory tract cellular immunity increased significantly. ► The level of anti-Mhp SIgA antibody in nasal secretion increased significantly. ► The level of systemic IgG antibody peaked at 35 day post-immunization.