highly significantP < 0.001
4 b, c) that both the FHCDV group and the FHCDV + CpG group of the nasal mucosal immunization group could induce highly significant levels of sIgA in nasal wash and bronchoalveolar lavage fluid ( P < 0.001), which were highly significant higher than those in the PBS group ( P < 0.001).And it can also be seen from the figure that the sIgA antibody titer produced in bronchoalveolar lavage fluid by the FHCDV + CpG group was significantly lower than that of the FHCDV group ( P < 0.01), suggesting that CpG adjuvant did not have an enhancement effect on the production of nasal mucosal immune response by FHCDV.