The antiviral activity of iIFN1a against IHNV was 1.69 × 107 U/mg in CHSE-214 cells.
The iIFN1a was potent to induce the antiviral state in vivo promptly.
The iIFN1a can completely protect the fish from the IHNV challenge within 1 dpi.
The variant protection correlated closely with the kinetic profile of antiviral state.