In the present study, fish received orally a single dose of
RGNNV VLPs (0.6 mg/g of fish body) without adjuvant, and
those showed just 57% of survival rate against RGNNV
challenge (Fig. 3) although this elicited a considerable level
of neutralizing antibody (Table 1, Fig. 2B). It is thought that
microencapsulation of the VLPs may improve the protective
immunity against RGNNV.