Orthopoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. The orthopoxvirus genus consists of 12 viruses including variola virus, vaccinia virus (VV), cowpox viruses (CV), monkeypox virus, and camelpox virus.

There are not many drugs available for orthopoxvirus treatment. The only product currently available for treatment of complications of Orthopoxvirus infection is vaccinia immunoglobulin (VIG).