variola virus vs poxvirus

variola virus and poxvirus both are nouns.

Word	Noun	Adjective	Verb	Adverb
variola virus	Yes	No	No	No
poxvirus	Yes	No	No	No

As nouns, poxvirus is a hypernym of variola virus; that is, poxvirus is a word with a broader meaning than variola virus:

variola virus: the virus that causes smallpox in humans; can be used as a bioweapon
poxvirus: any of a group of viruses that can cause pox diseases in vertebrates

variola virus (noun)	poxvirus (noun)
the virus that causes smallpox in humans; can be used as a bioweapon	any of a group of viruses that can cause pox diseases in vertebrates