The present invention discloses a novel apathogenic viral strain useful in the treatment of viral hepatitis infections. The preferred viral strain of Infectious Bursal Disease Virus (IBDV) is specifically characterized in terms of structure and biological activities. The invention also provides recombinant IBDV viral vectors for the inclusion of exogenous nucleic acid sequences enhancing the viral replication inhibitory effect of the virus of the invention. Preferably, the viral vector comprises a nucleic acid sequence encoding a cytokine. A method of treating viral hepatitis in a host comprising administering an anti-hepatitis effective amount of the IBDV strain of the present invention also provided.
