Weapon Store of Contagious Ecthyma Virus: Accounting for Immune Evasion and Re-Infection Strategies in Target Hosts

| Orf otherwise known as contagious ecthyma is a mild, self-limiting, localized skin disease of small ruminant's viz. sheep and goats, ensuring its presence and related economic loss all over the world. The virus is the prototype member of the Parapoxvirus genus of the Poxviridae family and is known to cause zoonotic affection sporadically. The main attraction to this virus has always been its wide range of virulence factors, known to be responsible for deceiving the host's defense strategies and causing re-infection within a year of infection. From viroceptors like chemokine binding protein to GM-CSF and IL-2 inhibiting factors, to virokine like Interleukin-10, shifting the cell cycle phase (Poxviral anaphase-promoting regulator complex) and enhancing nutrients and oxygen supply (vascular endothelial growth factor), ORFV possesses several unique strategies, to fight against host immune environment. Some of the genes have been acquired from the host and some are flowing through the family and genus evolving with the virus to adapt and efficiently set up an infection in immune-loaded host cells. This review focuses on the important virulence genes of the orf virus and their functions with recent advances and the way they can be manipulated for different benefits to the research community viz candidates for cancer biotherapy, immunomodulators, antivirals, viral vectors, and recombinant vaccines.