Monkeypox virus (MPXV), which can cause monkeypox (MPX), is a zoonotic enveloped dsDNA virus that belongs to the orthopoxvirus genus of the Poxviridae family. 

There are two clades of the Monkeypox virus, the West African clade and the Congo Basin clade. The West African clade is associated with the milder clinical presentation while the Congo Basin clade is more pathogenic and associated with greater human-to-human transmission. Human infections with the Monkeypox virus have similar clinical signs to smallpox but in a less severe form. The fatality rate of each clade is 0-6% and 8-13%. Cases detected in May were identified as being infected with the West African clade. 

The smallpox vaccine, to some extent, can protect people from infecting with MPXV. Antiviral treatment of accidental smallpox can also be applied to treat MPXV infection. But Smallpox has been eradicated for decades, these treatments cannot be applied on a large scale to treat monkeypox. We still need to do more research on monkeypox virus.