Fig. 4: Determination of immune responses.

a Specific antibody titer against the SN virus. b Specific antibody titer against the YZ4 virus. c Specific antibody titer against the SN virus at 42 d.p.i. d Specific antibody titer against the YZ4 virus at 42 d.p.i. e–h Cytokine level measurement after primary immunization. i–l Cytokine level measurement after booster immunization. m, n Detection of lymphocyte proliferation. o, p ELISpot detection after the YZ4 and SN viruses stimulation. Statistical analysis was performed using the one-way ANOVA. Error bar, mean ± SD.