vaccinia gangrenosa vs vaccinia

vaccinia gangrenosa and vaccinia both are nouns.

Word	Noun	Adjective	Verb	Adverb
vaccinia gangrenosa	Yes	No	No	No
vaccinia	Yes	No	No	No

As nouns, vaccinia is a hypernym of vaccinia gangrenosa; that is, vaccinia is a word with a broader meaning than vaccinia gangrenosa:

vaccinia gangrenosa: a severe or even fatal form of vaccinia that occurs mainly in persons with an immunological deficiency; characterized by progressive enlargement of the initial lesion
vaccinia: a local infection induced in humans by inoculation with the virus causing cowpox in order to confer resistance to smallpox; normally lasts three weeks and leaves a pitted scar

Other hypernyms of vaccinia gangrenosa include vaccina, variola vaccina, variola vaccine, variola vaccinia.

vaccinia gangrenosa (noun)	vaccinia (noun)
a severe or even fatal form of vaccinia that occurs mainly in persons with an immunological deficiency; characterized by progressive enlargement of the initial lesion	a viral disease of cattle causing a mild skin disease affecting the udder; formerly used to inoculate humans against smallpox
	a local infection induced in humans by inoculation with the virus causing cowpox in order to confer resistance to smallpox; normally lasts three weeks and leaves a pitted scar