Fig. 7

Immune response in vaccinated fish. a Schematic illustration to show the SVCV challenge experiment design. b Specific antibody levels of fish vaccinated with vaccines. c qRT-PCR analysis of the expression of immune genes in common carp via bath administration. d Enzyme activities in vaccinated common carp. Data are means for three assays and represented as mean ± SD. Data at the same sampling time with different letters are significantly different (P < 0.05). e Relative percentage survival after artificial challenging with SVCV in vaccinated common carp. The percentage survival was recorded daily and calculated at the end of the monitored period. P values were calculated by Log-rank (Mantel–Cox) Test (*P < 0.05, **P < 0.01)