Fig. 1. Experimental design of vaccine trial II. Olive flounder were vaccinated by polyinosinic
polycytidylic acid (Poly(I:C)) immunization with live viral hemorrhagic
septicemia virus (VHSV) or by intraperitoneal injection of formalin-treated (FT) VHSV.
Immunization was followed by VHSV challenge and collection of sera for antibody
detection by ELISA. VHSV 6, VHSV 5, and VHSV 4 indicate doses of 106, 105, and 104
TCID50 100 mL1 fish1, respectively. DEPC: diethylpyrocarbonate.