The present invention relates to the combination of attenuated non-pathogenic avian double-stranded (ds) RNA viral vector (IBDV) with an anti-PD-1 antibody and/or an anti-CTLA-4 antibody for treating Hepatitis B virus (HBV) infection.

Provided are compositions and methods for prophylaxis or therapy of cancer. The compositions and methods include use of Birnaviridae double stranded RNS (dsRNA) viruses for treating cancer in individuals that are not the normal virus hosts. Modifications of the dsRNA viruses are provided and include genetic changes that result improvements in anti-cancer therapy by increasing onxotoxicity of the modified viruses, and by including sequences encoding therapeutic pay loads.

The present invention provides recombinant herpes virus of turkeys (HVT) viral vectors comprising a heterologous polynucleotide encoding an avian influenza antigen. The recombinant viral vectors are suitable for use in immunogenic compositions and vaccines, and can provide protection against avian influenza and other pathogens when administered to an avian.