While your particular
medal of
Alexander VII isn't listed, there is another
medal listed in
Roma Resurgens: Papal Medals from the Age of the Baroque (a book I highly recommend). Here's the quote from page 97:
"No disease was more widespread or dreaded in seventeenth-century Europe than the plague. Epidemics spread from
London to Naples, and
Rome was fortunate in being less frequently and less severely afflicted than many cities. The worst came in May 1656 when an outbreak that
had already devastated Naples suddenly appeared in
Rome. To
his credit,
Alexander handled the situation with deft administrative skill and real human sympathy. He immediately left Castel Gandolfo upon hearing the news and returned to
Rome, where he took measures to safeguard the city. He organized a special
health commission, restricted entry through the
city gates, isolated quarters of the city, required registration of all cases, closed schools, screened confessionals, and established special hospitals, sanitariums, and burial places for the victims. Despite these efforts and
his own
courage in taking to the streets to reassure the public,
Rome lost 15,000 people, or one-eighth of its population, in a year's time. The issuance of this
medal [not yours, but the one cited in the book] on June 20, 1657 came just as the pestilence ended."
Your
medal is listed as
Mazio 255 in
A Pictorial Catalogue of Papal Medals 1417-1942 as Struck by the Mint of Rome for the VaticanYour Gregory XIII
medal is listed as
Mazio 110 in the same book.