vaccinia gangrenosa vs vaccina

vaccinia gangrenosa and vaccina both are nouns.

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

As nouns, vaccina is a hypernym of vaccinia gangrenosa; that is, vaccina 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
vaccina: 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 vaccinia, variola vaccina, variola vaccine, variola vaccinia.

vaccinia gangrenosa (noun)	vaccina (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 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